• Asian Pacific Journal of Cancer Prevention
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• v.15 no.12
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• pp.4815-4821
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• 2014

Background: This study aimed to examine the relationship between respiratory health of Malaysian adolescents with secondhand smoke (SHS) exposure and smoke-free legislation (SFL) implementation. Materials and Methods: A total of 898 students from 21 schools across comprehensive- and partial-SFL states were recruited. SHS exposures and respiratory symptoms were assessed via questionnaire. Prenatal and postnatal SHS exposure information was obtained from parental-completed questionnaire. Results: The prevalence of respiratory symptoms was: 11.9% ever wheeze, 5.6% current wheeze, 22.3% exercise-induced wheeze, 12.4% nocturnal cough, and 13.1% self-reported asthma. SHS exposure was most frequently reported in restaurants. Hierarchical logistic regression indicates living in a comprehensive-SFL state was not associated with a lower risk of reporting asthma symptoms. SHS exposure in public transport was linked to increased risk for wheeze (Adjusted Odds Ratio (AOR) 16.6; 95%confidence interval (CI), 2.69-101.7) and current wheezing (AOR 24.6; 95%CI, 3.53-171.8). Conclusions: Adolescents continue to be exposed to SHS in a range of public venues in both comprehensive- and partial-SFL states. Respiratory symptoms are common among those reporting SHS exposure on public transportation. Non-compliance with SFL appears to be frequent in many venues across Malaysia and enforcement should be given priority in order to reduce exposure.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.317-324
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• 2014

Environmental tobacco smoke (ETS) samples were collected separately in mainstream and side-stream smoke using a self-designed smoking machine, and a total 40 of PM2.5 was collected with low volume air sampler at indoor environments with and without ETS in Daejeon, Korea. About 20 trace elements including toxic metals like As, Cr, Mn, Se, V, and Zn were determined in PM2.5 and ETS samples by instrumental neutron activation analysis (INAA). It is found that the emission factors of K, Cl, Na, and Al were much higher than those of toxic elements for both mainstream and side-stream smoke. The average concentration of PM2.5 was enriched by 1.5 times at smoking area ($58.7{\pm}18.1{\mu}g/m^3$) than at smoking free area ($38.6{\pm}12.7{\mu}g/m^3$). The concentration ratio of each element between smoking and smoking free area were ranged from 1.1 to 6.0 except Cu (1.0); especially, Ce (6.0), La (5.2), K (2.3), and Co (2.0) showed higher ratio, which suggests that the ETS is one of the possible increasing factors of PM2.5 and elemental concentration at indoor environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1017-1026
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• 2016

The present paper describes the two off-surface visualization techniques and their application examples to vortex flows. One of the two visualization techniques is the classical smoke-wire technique, and the other is the visualization technique using the micro water-droplets generated by the home-style ultrasonic humidifier. The smoke-wire technique has the limit of air flow speed (about 5 m/sec for 0.07 mm-diameter wire) and the pollution problem, but it produces very fine and clear streak line sheet. It is applied to visualize the wing-tip vortices of a 3-dimensional wing. The micro water-droplet technique has the larger limit of air flow speed (above 10 m/sec) and is free from pollution and toxic problems compared to the smoke-wire technique. It is successfully applied to visualize the complex vortex system of a double-delta wing with an apex strake.

• Journal of Environmental Health Sciences
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• v.41 no.2
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• pp.126-132
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• 2015

Objectives: The Korean government implemented a smoke-free regulation for pubs with a net indoor area of ${\geq}100m^2$ on January 1, 2014. The purpose of this study was to determine the indoor levels of concentrations of particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$) in implemented and non-implemented pubs in Seoul and Changwon. Methods: $PM_{2.5}$ concentrations in fifty-two $100-150m^2$ (implemented) and fifty-seven < $100m^2$ (non-implemented) pubs were measured. A real-time aerosol monitor was used to measure $PM_{2.5}$ concentrations. Field technicians recorded characteristics of the pubs including net indoor area, indoor volume and presence of smoking rooms and counted the number of burning cigarettes, patrons and vents. Results: Differences between indoor and outdoor $PM_{2.5}$ concentrations in $100-150m^2$ and < $100m^2$ pubs were not significantly different in each city. Smoking was observed in 33% of $100-150m^2$ pubs and 51% of < $100m^2$ pubs. Average differences between indoor and outdoor $PM_{2.5}$ concentrations in the $100-150m^2$ and < $100m^2$ pubs were $79.2{\mu}g/m^3$ and $155.6{\mu}g/m^3$, respectively. When smokers were not observed, differences between indoor and outdoor $PM_{2.5}$ concentrations ware $12.4{\mu}g/m^3$ in $100-150m^2$ pubs and $24.5{\mu}g/m^3$ in < $100m^2$ pubs. Conclusion: Although the regulation was implemented only in ${\geq}100m^2$ pubs, a higher difference between indoor and outdoor $PM_{2.5}$ concentrations was observed in implemented and non-implemented pubs with smokers. Strict implementation of the regulation in all pubs is needed for better indoor air quality.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.6
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• pp.80-89
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• 2004

In order to confront the increasing air pollution and the tightening emission restrictions, this research developed a diesel engine using DME, the advanced smoke-free alternative fuel. By numerical analysis, flow field, spray, and combustion phenomenon of the DME engine was presented. Using an experimental method, the configuration of the fuel supply system and operation/power performance was tested with the current plunger pump. Most emission performance, especially smoke performance was significantly improved. The possibility of conversion from the current diesel engine into the DME engine was affirmed in this research. However, it was found that the increase of engine RPM and fuel amount need to be properly adjusted through matching the characteristics of fuel and injector for further improvement.

• Journal of the Korea Safety Management & Science
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• v.23 no.4
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• pp.67-72
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• 2021

To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.

• Journal of Environmental Health Sciences
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• v.29 no.3
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• pp.35-42
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• 2003

Nitric Oxide(NO) is produced in many organs of the body, including the lung and airways, and it is detectable in the exhaled air. The measurement of exhaled NO(eNO) provides a simple non-invasive means for measuring airway inflammation, such as asthma. We measured eNO among adult male workers to examine the distribution of eNO in healthy people and to find factors affecting eNO. We measured eNO in a sample of 921 adult workers who also performed lung function test and skin prick test. Exhaled NO was measured in a sitting posture without using a nose clip and NO free gas. NO was measured at three expiratory rates(l8; 42; 71 $m\ell$/sec) and the flow rate of 71 $m\ell$/sec was used in analysis. The average eNO concentration was 5.29 $\pm$ 2.98 ppb. The level increased with age but not significantly(P=0.0529). Exhaled NO showed positive relations to the height(P=0.0001), pollen 1 (P=0.0124), asthma history(P=0.0212), allergic rhinitis symptom(P=0.0302). Exhaled NO Concentration of smokers( 4.62 ppb) was significantly lower than that of nonsmokers(5.99 ppb; P<0.0001).

• Journal of Sericultural and Entomological Science
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• v.23 no.1
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• pp.47-55
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• 1981

Silk textile finishing has been studied for many years by many workers in order to meet more utilities for various endusers. Such studies, however, could not be successful because any natural fibers are hardly change their natures by artificial treating methods. Textile finishing is of course to improve the mechandise qualities and the poor natures of silk so that it may be available as the best textile fiber in the world. Sometimes, famous trade marked textile plays more power than its quality in the silk market, nevertheless, this should be over line of research activities. Meantime, the silk demand has been also transferred from ladies stocking to other clothes since nylon or other synthetic fibers were developed. That is why, the extension of silk demand should be developed by various research works. Specially, silk is known as difficult textile to handle it during washing or ironing process which happened to depress down the silk usage for house wives. In order to solve such problems, the reporter has been worked for many years and now, he believes that he has developed a proper finishing method to coversuch problems. The developed finishing method may be said to eligible with economical aspect and shorten the dry duration after water washing in half against normal silk textile without harming the specific silk nature. As all of us know, silk fiber starts to denature since it was spinned by silkworm and the fiber is formed as overlapped "S" type curves during its concooning process. After it is made as raw silk or sericin silk, it shows as straight line form, but it changes in to waved form in case refining or degumming process in order return to its original spinned form. Such nature is continued during its textile form and ends with hard ironing nature than other textile fibers. Mean while, the silk fiber keeps to continue its denaturing and this is iniciated by repeat of washing and drying which takes many years to reach its final stage, The reporter has found the iniciating denature of silk by his finishing process, with out heat, decreasing the swollen nature which ended with shortening the drying duration after wash. Each washing was carried out by soaking the previously weighed sample in cold water for one hour, then pressed the sample for ten minutes to eliminate its free water component before weighing with same condition. According to this, the treated silk showed much denaturing after the finishing, but the standard silk progressed the denaturing by and by with the repeat of washing and drying, finally reached the same swollen degree of treated silk, Such treating result explains that the treated silk happened to be stebilized nature by the treating immediately. On the other that the treated silk happened to be stebilized nature by the treating immediately. On the other hand, standard silk may reach to such condition by the time of worn out clothes after repeat of washing and drying for many years while the clothes will be no more useful. The decreased swelling nature has brought about the drying period in half against standard silk after all. Not only the tests of tenacity and elongation but also crease resistance recovery, stiffness and shrinkage tests were carried out after each washing and drying which he has found better result on the treated silk textile against the standard silk. The most important thing was to keep the textile feeling of silk by such finishing work before improve any poor nature of silk. The general silk has a nature to absorb smoke or dirt from its surrounding air and reaches to dirty color shade upon such exposure, but the treated one has improved such nature because of its artificial denaturing, another word, it keeps clean longer than the normal silk. Many previous finishing works could improve some specific nature of silk, but it happened to deprave other important natures. The reporters work is, however, specialized to improve the silk to be useful as Wash and Wear Silk without harming its standard natures. So far, this work happened to be a overall innovative finishing method of silk textile.