http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Choosong, Thitiworn,Phakthongsuk, Pitchaya,Tekasakul, Surajit,Tekasakul, Perapong Occupational Safety and Health Research Institute 2014 Safety and health at work Vol.5 No.2
Background: Urinary 1-hydroxypyrene (1-OHP) was selected as a biomarker of polycyclic aromatic hydrocarbons (PAHs) to explore the accumulation level in the bodies of workers at rubber smoke sheet factories in southern Thailand. Methods: Spot urine samples were taken from four groups of workers from June 2006 to November 2007. The nonexposure or control groups included habitual cigarette smokers and nonsmokers. The other two groups were workers exposed to particle-bound PAHs from rubber wood smoke and they were nonsmokers. All spot urine samples were analyzed for 1-OHP and creatinine levels. Results: The mean${\pm}$standard deviation urinary 1-OHP in the control group of habitual smokers and the nonsmokers was $0.24{\pm}0.16{\mu}mol/mol$ creatinine and not-detected to $0.14{\mu}mol/mol$ creatinine, respectively. In the workers, the 1-OHP levels on workdays had no significant difference from the 1-OHP levels on the days off. The yearly average 1-OHP level was $0.76{\pm}0.41{\mu}mol/mol$ creatinine whereas the average 1-OHP level during 10 consecutive workdays was $1.06{\pm}0.29{\mu}mol/mol$ creatinine (p > 0.05). Conclusion: The urinary 1-OHP levels of workers exposed to PAHs were high. The accumulation of 1-OHP in the body was not clear although the workers had long working hours with few days off during their working experience. Therefore, a regular day off schedule and rotation shift work during high productive RSS should be set for RSS workers.
Thitiworn Choosong,Pitchaya Phakthongsuk,Surajit Tekasakul,Perapong Tekasakul 한국산업안전보건공단 산업안전보건연구원 2014 Safety and health at work Vol.5 No.2
Background: Urinary 1-hydroxypyrene (1-OHP) was selected as a biomarker of polycyclic aromatic hydrocarbons (PAHs) to explore the accumulation level in the bodies of workers at rubber smoke sheet factories in southern Thailand. Methods: Spot urine samples were taken from four groups of workers from June 2006 to November 2007. The nonexposure or control groups included habitual cigarette smokers and nonsmokers. The other two groups were workers exposed to particle-bound PAHs from rubber wood smoke and they were nonsmokers. All spot urine samples were analyzed for 1-OHP and creatinine levels. Results: The mean ? standard deviation urinary 1-OHP in the control group of habitual smokers and the nonsmokers was 0.24 ? 0.16 mmol/mol creatinine and not-detected to 0.14 mmol/mol creatinine, respectively. In the workers, the 1-OHP levels on workdays had no significant difference from the 1-OHP levels on the days off. The yearly average 1-OHP level was 0.76 ? 0.41 mmol/mol creatinine whereas the average 1-OHP level during 10 consecutive workdays was 1.06 ? 0.29 mmol/mol creatinine (p > 0.05). Conclusion: The urinary 1-OHP levels of workers exposed to PAHs were high. The accumulation of 1-OHP in the body was not clear although the workers had long working hours with few days off during their working experience. Therefore, a regular day off schedule and rotation shift work during high productive RSS should be set for RSS workers.
Makatar Wae-hayee,Perapong Tekasakul,Smith Eiamsa-ard,Chayut Nuntadusit 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7
An effect of cross-flow velocity on flow and heat transfer characteristics of impinging jet in the case of low jet-to-plate distance at H =2D was experimentally and numerically investigated. In the experiments, the air jet from orifice impingement on the wall of wind tunnelwhile a cross-flow was simultaneously induced normal to the jet flow. The jet velocity was fixed while the cross-flow velocity was variedcorresponding to velocity ratios (jet velocity/cross-flow velocity) VR = 3, 5 and 7. The temperature distribution on an impinged surfacewas visualized by using thermochromic liquid crystal sheet (TLCs), and Nusselt number distribution was evaluated by using image processingmethod. The flow pattern on impingement surface was visualized by using oil film technique. The numerical simulation was carriedout for a better understanding of the jet flow in the cross-flow. The results show that Nusselt number peak shifts downstream and theNusselt number peak increases with increasing cross-flow velocity.
Effects of torrefaction on physical properties, chemical composition and reactivity of microalgae
Neeranuch Phusunti,Worasak Phetwarotai,Surajit Tekasakul 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.2
Torrefaction of the microalga Chlorella vulgaris was carried out in a fixed-bed tubular reactor under various conditions of temperature (150-300 oC), time (15-60min), and atmosphere (inert or oxidative). The impact of torrefaction and its various conditions on the mass yield, physical properties, chemical composition, and reactivity of the microalgal biomass was assessed and compared with those of the raw material. After torrefaction, the morphology, proximate analysis, ultimate analysis, higher heating value analysis, chemical compositions, and thermal behavior of the biomass were carried out. The results show that torrefaction temperature influenced mass yield and changes in the microalgae’s properties more than torrefaction time and atmosphere. Torrefaction at 200 oC, for 30min in an inert atmosphere led to the highest calorific value of torrefied microalgae. In addition, torrefaction reduced the thermal degradation rates of the remaining protein and carbohydrate fractions in the biomass, but accelerated the degradation rate of the lipids fraction.