• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.8-13
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• 2008

Emissions from automobiles have long been considered a prime source of pollutants involved in smog formation and ozone production. Especially VOCs are associated with serious environmental problems such as photo-chemical smog as well as human health effects. Since motor vehicles are a major source of VOCs, estimating of emission from mobile source is the most important factor to control VOCs. VOCs are emitted from various pollution like motor vehicles, mobile and stationary source that has characteristics of toxicity, cancer-causing, bio-accumulation, durability in air and diffusion can exert a bad influence upon human health and environment. However we don't have any standard or regulation about VOCs emissions. This study is summarized as VOCs emission characteristics from in-use light-duty diesel and LPG fueled vehicles. The vehicle exhaust-gas test mode is CVS cycle and nier-10 cycles that developed on EPA and National Institute of Environmental Research. TO-14 method (Toxic Organic) was chosen for VOCs analysis from EPA in USA. This study results will be useful when make a emission factor and rule making of emission standard about domestic VOCs emission for the improve to air condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.29-35
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• 2012

Special attention in the role of convection in vapor crystal growth has been paid since some single crystals under high gravity acceleration of $10g_0$ appear considerably larger than those under normal gravity acceleration ($1g_0$). With increasing the gravity acceleration from $1g_0$ up to $10g_0$, the total molar flux for ${\Delta}T$ = 30 K increases by a factor of 4, while for ${\Delta}T$ = 90, by a factor of 3. The maximum molar fluxes for three different gravity levels of $1g_0$, $4g_0$ and $10g_0$, appear approximately in the neighborhood of y = 0.5 cm, and the molar fluxes show asymmetrical patterns, which indicate the occurrence of either one single or more than one convective cell. As the gravitational level is enhanced form $1g_0$ up to $10g_0$, the intensity of convection is increased significantly through the maximum molar fluxes for ${\Delta}T$ = 30 K and 90 K. At $10g_0$, the maximum total molar flux is nearly invariant for for ${\Delta}T$ = 30 K and 90 K. The total molar flux increases with increasing the gravity acceleration, for $1g_0{\leq}g_y{\leq}10g_0$, and decreases with increasing the partial pressure of component B, a noble gas called as Kr (Krypton), $P_B$. The ${{\mid}U{\mid}}_{max}$ is directly proportional to the gravity acceleration for 20 Torr $P_B{\leq}300$ Torr. As the partial pressure of $P_B$ (Torr) decreases from 300 Torr to 20 Torr, the slopes of the ${{\mid}U{\mid}}_{max}s$ versus the gravity accelerations increase from 0.29 sec to 0.54 sec, i.e. by a factor of 2. The total molar flux of $Hg_2Cl_2$ is first order exponentially decayed with increasing the partial pressure of component B, $P_B$ (Torr) from 20 Torr up to 300 Torr.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.98-104
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• 2009

The objective of this study was to characterize quality changes of PET-packaged green tea beverage during 4-week storage at $60^{\circ}C$. Changes in oxygen transmission of the PET bottle package and cap removal torque were also examined. MXD6 blend PET bottle showed stability in the gas barrier. Its cap removal torque was kept stable during the 4 weeks. pH, color value, contents of vitamin C and catechin showed significant changes during the storage while caffeine and amino acid did not change significantly. Four alcohol flavor components (hexanol, linalool, menthol, and ${\alpha}$-terpineol) increased rapidly during the first three weeks while d-limonene did not show significant change. Sensory test showed decrease in astringent flavor lowering the product flavor and acceptability.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.9
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• pp.1081-1086
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• 2014

An experimental study was performed in order to compare with the case of using pure diesel the characteristics of combustion pressure and exhaust emissions when the engine speed was changed in a CRDI 4-cylinder diesel engine using biodiesel( Canola oil) blended and pure diesel fuel. As a results, the combustion pressure was decreased with increasing biodiesel blended rate when engine speed was 1,000, 1,500, 2000(rpm). but the combustion pressure of the engine speed 2,500rpm was increased with increasing biodiesel blended rate. The emission results show, that CO was decreased with increasing biodiesel blended rate and engine speed. The emission of $CO_2$, NOx, were increased with increasing biodiesel blended rate and engine speed.

• The Korean Journal of Community Living Science
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• v.23 no.2
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• pp.129-136
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• 2012

Dioxins are chemical substances that are not properly decomposed degradation under natural photochemical, biological and chemical conditions in the environment, and bio-accumulate through the food chain, so pose a risk of causing adverse effects to human health and the environment. Ninety seven percent of human exposure to dioxins comes through meat, fish, dairy consumption and so on. Pork is the largest proportion meat aspect of daily intake in the Korean food. Pigs are three times more than Cattle in terms of breeding population and production amount in the world, and the amount is increasing every year. Therefore, it is necessary to monitor the exposure level of dioxins in pig's body. Also, it is required to evaluate the presence of these chemical substances in the pig's feed grain such as corn, soybeans, and tallow. The purpose of this study was to evaluate PCDD/Fs in pig's feed to search the origin of PCDD/Fs. Feed samples obtained were wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1613. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). The concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PCDD), which are the most toxic potent dioxins, were not observed in any of the samples. However OCDD was detected in most of the samples. The TEQs in the feed samples were ranged from 0 pg TEQ/g to 0.09841 pg TEQ/g. Especially, the high level of TEQs was observed in the samples of wheat from East Europe and soybean meal from Korea.

• Journal of the Korean Chemical Society
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• v.32 no.5
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• pp.422-427
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• 1988

The bio-electrode for L-asparagine, excellent in the reproducibility of responsibility, has been constructed by immobilizing the bacterium Proteus mirabilis on an ammonia gas sensor. This electrode was investigated for the effects of pH, temperature, buffer solution, bacterial amounts and interferences, and stability with the lapse of time. The response of the bacterial electrode was linear in the range of $9.0{\times}10^{-5}$ ∼ $1.0{\times}10^{-2}M$ L-asparagine with a slope of 58.9mV/decade in pH 7.8, 0.05M phosphate buffer solution at $30^{\circ}C$. The bacterial amounts used for this electrode was 3 mg and response time was 7∼9 min. Therefore, this assembly can be used for the determination of L-asparagine.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.15-26
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• 2006

As traffic in city-centre around the world continues to increase, so levels of atmospheric pollutants continue to rise. High concentrations of NOx can have negative effects on human health, and we must find new ways to reduce their levels in the air we breathe. Nitrogen oxide gas (NOx), consisting of nitrogen monoxide (NO) and nitrogen dioxide $(NO_2)$ produced using $O_3$ oxidation, at a low concentration corresponding to that on roads as a result of exhaust from automobiles, was carried out to evaluate the removal characteristics of NOx through a laboratory-scale biofilter packed with soil as a packing material. A mixture media (yellow soil (30%): soil (40%): compost (10%): a used briquet (20%)) was applied. After about 1day of operation, the removal efficiency for $NO_2$ in all experiments with a constant condition ($25^{\circ}C$ and water humidity (60%)) was over 98%. The retention times of the section between phase I and phase II for formation and reduction of $NO_3$ NO and $NO_2$ on the initial $NO_3$ concentration was 50min $(O_3:195\;ppb),\;55min\;(O_3:925\;ppb),\;65min\;(O_3:1743\;ppb),\;70min\;(O_3:2616\;ppb),\;75min\;(O_3:3500\;ppb)$, respectively The soil biofilter system is a unique technology that purifies urban air by utilizing the natural processes that take place in the soil. Although some of the processes are quite complex, they can broadly be summarized as adsorption onto soil particles, dissolution into soil pore water, and biochemical.

• Transactions of the KSME C: Technology and Education
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• v.1 no.2
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• pp.193-198
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• 2013

The horseback riding simulator, an exercise training machine providing a simplified horse riding motion has been developed for aiming at healthcare. The purpose of this study was to estimate the energy expenditure without measuring bio-signals using the simulator. The test protocol was consisted of increase up to maximal intensity(Motion 9) and decrease down to minimal intensity(Motion 4) during 25 minutes, and energy expenditure was measured by portable cardiopulmonary exercise testing analyzer. There were significant differences in energy expenditure according to each riding motion. The result will be able to estimate energy expenditure using motion level, exercise time, age and gender during the riding.

• Nutrition Research and Practice
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• v.12 no.1
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• pp.3-12
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• 2018

BACKGROUND/OBJECTIVES: Sageretia thea is traditionally used as a medicinal herb to treat various diseases, including skin disorders, in China and Korea. This study evaluated the inhibitory effect of Sageretia thea fruit on melanogenesis and its underlying mechanisms in B16F10 mouse melanoma cells. The active chemical compounds in anti-melanogenesis were determined in Sageretia thea. MATERIALS/METHODS: Solvent fractions from the crude extract were investigated for anti-melanogenic activities. These activities and the mechanism of anti-melanogenesis in B16F10 cells were examined by determining melanin content and tyrosinase activity, and by performing western blotting. RESULTS: The n-hexane fraction of Sageretia thea fruit (HFSF) exhibited significant anti-melanogenic activity among the various solvent fractions without reducing viability of B16F10 cells. The HFSF suppressed the expression of tyrosinase and tyrosinase-related protein 1 (TRP1). The reduction of microphthalmia-associated transcription factor (MITF) expression by the HFSF was mediated by the Akt/glycogen synthase kinase 3 beta ($GSK3{\beta}$) signaling pathway, which promotes the reduction of ${\beta}-catenin$. Treatment with the $GSK3{\beta}$ inhibitor 6-bromoindirubin-3'-oxime (BIO) restored HFSF-induced inhibition of MITF expression. The HFSF bioactive constituents responsible for anti-melanogenic activity were identified by bioassay-guided fractionation and gas chromatography-mass spectrometry analysis as methyl linoleate and methyl linolenate. CONCLUSIONS: These results indicate that HFSF and its constituents, methyl linoleate and methyl linolenate, could be used as whitening agents in cosmetics and have potential for treating hyperpigmentation disorders in the clinic.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.530-537
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• 2015

The objective of this study was to evaluate the in vitro effects of flavonoid-rich plant extracts (PE) on ruminal fermentation characteristics and methane emission by studying their effectiveness for methanogenesis in the rumen. A fistulated Holstein cow was used as a donor of rumen fluid. The PE (Punica granatum, Betula schmidtii, Ginkgo biloba, Camellia japonica, and Cudrania tricuspidata) known to have high concentrations of flavonoid were added to an in vitro fermentation incubated with rumen fluid. Total gas production and microbial growth with all PE was higher than that of the control at 24 h incubation, while the methane emission was significantly lower (p<0.05) than that of the control. The decrease in methane accumulation relative to the control was 47.6%, 39.6%, 46.7%, 47.9%, and 48.8% for Punica, Betula, Ginkgo, Camellia, and Cudrania treatments, respectively. Ciliate populations were reduced by more than 60% in flavonoid-rich PE treatments. The Fibrobacter succinogenes diversity in all added flavonoid-rich PE was shown to increase, while the Ruminoccocus albus and R. flavefaciens populations in all PE decreased as compared with the control. In particular, the F. succinogenes community with the addition of Birch extract increased to a greater extent than that of others. In conclusion, the results of this study showed that flavonoid-rich PE decreased ruminal methane emission without adversely affecting ruminal fermentation characteristics in vitro in 24 h incubation time, suggesting that the flavonoid-rich PE have potential possibility as bio-active regulator for ruminants.