• Journal of Sensor Science and Technology
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• v.33 no.1
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• pp.1-6
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• 2024

This study aims to suggest the partition ratio (Q-factor) of healthy Koreans and the comparison results of breath alcohol concentration (BAC) measurements using two methods (photoacoustic and electrochemical methods) for developing breath alcohol ignition interlock devices (BAIIDs). Given the relationship between BACs and BrACs and the Q-factor, the alcohol metabolism of healthy Koreans (96 males and 91 females) is revealed for understanding the digestion of alcohol and surveying the fundamental data of alcohol-related problems, CO₂ concentrations vs. alcohol concentrations, and the performance of alcohol sensors in the marketplace. The average Q-factor of healthy Korean males and females are 1,913 (95% confidence interval from 1,889-1,937) and 1,991 (95% confidence interval from 1,945-2,036). Photoacoustic measurements could be applied to predict the BACs of drinkers, which is confirmed by the Bland-Altman plots presented in this study. The biases based on the partition ratios (Q=1,913 and Q=1,991) in the Bland-Altman plots were -0.0004% (95% CI from -0.0011 to +0.0003% for males) and -0.0017% (95% CI from -0.020 to +0.017% for females).

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.718-724
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• 2006

The heterogeneous association behaviour of various concentration binary mixtures of mono alkyl ethers of ethylene glycol with ethyl alcohol were investigated by dielectric measurement in benzene solutions over the entire concentration range at 25 ${^{\circ}C}$. The values of static dielectric constant $\epsilon_0$ of the mixtures were measured at 1 MHz using a four terminal dielectric liquid test fixture and precision LCR meter. The high frequency limiting dielectric constant $\epsilon_\infty$ values were determined by measurement of refractive index $n_D$ ($\epsilon_\infty\;=\;n_D\;^2$). The measured values of $\epsilon_0$ and $\epsilon_\infty$ were used to evaluate the values of excess dielectric constant $\epsilon^E$, effective Kirkwood correlation factor $g^{eff}$ and corrective correlation factor $g_f$ of the binary polar mixtures to obtain qualitative and quantitative information about the H-bond complex formation. The non-linear behaviour of the observed $\epsilon_0$ values of the polar molecules and their mixtures in benzene solvent confirms the variation in the associated structures with change in polar mixture constituents concentration and also by dilution in non-polar solvents. Appearance of the maximum in $\epsilon^E$ values at different concentration of the polar mixtures suggest the formation of stable adduct complex, which depends on the molecular size of the mono alkyl ethers of ethylene glycol. Further, the observed $\epsilon^E$ < 0 also confirms the heterogeneous H-bond complex formation reduces the effective number of dipoles in these polar binary mixtures. In benzene solutions these polar molecules shows the maximum reduce in effective number of dipoles at 50 percent dilutions. But ethyl alcohol rich binary polar mixtures in benzene solvent show the maximum reduce in effective number of dipoles in benzene rich solutions.

• Environmental Analysis Health and Toxicology
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• v.21 no.3 s.54
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• pp.229-238
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• 2006

Although, mercury (Hg) is not a naturally abundant element in the environment, residues frequently occur in many environmental compartments because of widespread contamination from industrial and agricultural practices. This research evaluated Hg-B concentrations of general population who was not occupationally exposed. And also evaluates the association between life factor and health effect with Hg-B concentration of general adult through interrelationship estimation and index about kidney function and oxidative damage that appeared by questionnaire survey and medical examination. Average concentration of Hg-B was 3.19 $\mu$g/L (ND$\sim$8.64 $\mu$g/L), and persons who exceed mercury exposure level (5 $\mu$g/L) presented in WHO (1990) appeared by 16 (7.0%). High-risk group (smoking and meat main intake group) had significantly higher Hg-B concentration than low-risk group (non-smoking and vegetable diet main intake group) (p < 0.05, low-risk group: 3.30 $\mu$g/L (ND$\sim$8.64 $\mu$g/L), high-risk group: 4.27 $\mu$g/L (ND$\sim$7.84 $\mu$g/L).

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.698-703
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• 1998

The pervaporation experiments of aqueous solutions of trichloroethylene (TCE) and chlorobenzene (CB) through the silicone rubber (polydimethylsiloxane, PDMS) membrane were carried out and the effect of concentration polarization on the separation characteristics was investigated. The resistance-in-series model was used to explain the boundary layer resistance. It was clear that the concentration polarization phenomenon had a significant effect on the permeation behavior in the pervaporation separation of the trace organic chlorides from aqueous solutions. With the same membrane thickness, the permeation of TCE, which has a stronger affinity for the PDMS, appeared to be more influenced by the boundary layer resistance than that of CB. The effect of boundary layer resistance was reduced and the membrane resistance became dominant with increasing membrane thickness at a given hydrodynamic condition. The separation factor was increased to approach the intrinsic separation factor of the membrane with its thickness.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1337-1350
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• 2023

Caproic acid is a precursor substance for the synthesis of ethyl caproate, the main flavor substance of nongxiangxing baijiu liquor. In this study, Clostridium butyricum GD1-1, a strain with high caproic acid concentration (3.86 g/l), was isolated from the storage pit mud of nongxiangxing baijiu for sequencing and analysis. The strain's genome was 3,840,048 bp in length with 4,050 open reading frames. In addition, virulence factor annotation analysis showed C. butyricum GD1-1 to be safe at the genetic level. However, the annotation results using the Kyoto Encyclopedia of Genes and Genomes Automatic Annotation Server predicted a deficiency in the strain's synthesis of alanine, methionine, and biotin. These results were confirmed by essential nutrient factor validation experiments. Furthermore, the optimized medium conditions for caproic acid concentration by strain GD1-1 were (g/l): glucose 30, NaCl 5, yeast extract 10, peptone 10, beef paste 10, sodium acetate 11, L-cysteine 0.6, biotin 0.004, starch 2, and 2.0% ethanol. The optimized fermentation conditions for caproic acid production by C. butyricum GD1-1 on a single-factor basis were: 5% inoculum volume, 35℃, pH 7, and 90% loading volume. Under optimal conditions, the caproic acid concentration of strain GD1-1 reached 5.42 g/l, which was 1.40 times higher than the initial concentration. C. butyricum GD1-1 could be further used in caproic acid production, NXXB pit mud strengthening and maintenance, and artificial pit mud preparation.

• Journal of the Korean Regional Science Association
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• v.9 no.1
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• pp.45-63
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• 1993

University enrollment has long been regarded as one of the major factors inducing population concentration in Seoul and the Capital Region of Korea. Consequently, since early 1980's increases in enrollment and new establishments of extention universities beyond the boundary of Seoul, has been promoted, while university enrollment quota in Seoul has been strictly controlled. The degree of actual population dispersal, however, resulting from such a university enrollment policy has not been empirically tested. This paper aims at: First, identifying the trend of population growth and evolution process of the university enrollment policy in the Capital Region; Second, comparing the degree of influence of university enrollment on population concetration factors; Third, measuring actual effect of the enrollment control on population dispersal out of Seoul and the Capital Region. Major findings are as follows: First, only a week correlation between population and university enrollment growth trends was found; Second, the relative degree of influence on population concentration in the Capital Region, were order, in the order of magnitude, the physical amenity factor, the socio-cultural amenity factor, the employment climate factor and the educational factor. Third, and most improtant, based on the comparison of spatial distribution of graduated high schools and current residence of the selected university students, the gap between the two distributions was revealed and the inter-regional student population movement was estimated. The result shows that in Seoul's case about one-half of and in Kyunggi Province's case about one-fifth of university enrollment size, contributes to population concentration into Seoul. Fourth, as to the universities outside of the Capital Region, little effect in the case of universities located within the commuting distance, and a little effect on population dispersal in the case of universities located beyond commuting distance, were found. In sum, it seems clear that university enrollment policy in the Capital Region, especially in Inchon/Kyunggi Province has not been effective on student population dispersal out of Seoul and the Capital Region. Therefore, it is strongly recommended that university enrollment policy be throughly re-examined from its goal to the implementation means.

• KSBB Journal
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• v.25 no.1
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• pp.11-17
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• 2010

Here, we evaluated the effect of thrombin on the interleukin-6 production induced by tumor-necrosis-factor-$\alpha$ in endothelial cells. It is well known that tumor-necrosis-factor-$\alpha$ mediates inflammatory responses by activation of nuclear factor-kappa-B in endothelial cells. Here, we showed that lower concentration of thrombin decreased the production of interleukin-6 induced by tumor-necrosis-factor-$\alpha$ and this inhibitory effect of thrombin on interleukin-6 production was mediated by interacting with protease-activated-receptor-1. In addition, phosphoinositide-3-kinase was also involved the anti-inflammatory responses by lower concentration of thrombin in endothelial cells. These results suggested that lower concentration of thrombin mediated anti-inflammatory responses by interacting with protease-activated-receptor-1 on the cell membrane and phosphoinositide-3-kinase in the cell. These findings will provide the important evidence in the development of new medicine for the treatment of severe sepsis and inflammatory diseases and good clue for understanding unknown mechanisms by which thrombin showed the pro-inflammatory or anti-inflammatory activities in endothelial cells.

• Archives of Plastic Surgery
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• v.36 no.1
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• pp.19-23
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• 2009

Purpose: Platelet transplantation is a novel therapeutic strategy for acceleration of wound healing. When applying platelets, efficacy of adding thrombin to stimulate growth factor release from platelets has already been proved. However, no quantitative data of the thrombin treatment has been reported. The purpose of this study was to determine the optimal thrombin concentration to maximize growth factor release of platelets. In particular, this study was designed to quantify levels of platelet derived growth factor(PDGF)-BB, which is a major growth factor contained in the platelets, in vitro. Methods: Fresh platelets were obtained from a blood bank. They were suspended in DMEM/F - 12 and incubated with thrombin of various concentrations. The concentrations of thrombin tested were 0, 6.25, 12.5, 25, 50, 100, 200, and 400 IU/ml. After 30 minutes, 1, 3, 5, and 7 days, the levels of PDGF - BB were measured using enzyme linked immunosorbent assay. Platelets from four donors were included in this study. Each sample was tested in triplicate and the mean value was used as a data for each sample. Results: The addition of thrombin increased the level of PDGF - BB. Increases in storage time of platelets resulted in decreased levels of PDGF - BB. Higher levels of PDGF were detected in consort with increased thrombin concentrations. However, there was no significant difference between samples of 200 and 400 IU/ml concentrations. Conclusion: The results indicate that adding thrombin accelerates the release of growth factors from platelets and the optimal thrombin concentration to maximize this function is 200 IU/ml.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.2 no.1
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• pp.35-40
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• 2004

Final disposal of radioactive waste generated from Nuclear Power Plant (NPP) requires the detailed information about the characteristics and the quantities of radionuclides in waste package. Most of these radionuclides are difficult to measure and expensive to assay. Thus it is suggested to the indirect method by which the concentration of the Difficult-to-Measure (DTM) nuclide is estimated using the correlations of concentration - it is called the scaling factor - between Easy-to-Measure (Key) nuclides and DTM nuclides with the measured concentration of the Key nuclide. In general, the scaling factor is determined by the log mean average (LMA) method and the regression method. However, these methods are inadequate to apply to fission product nuclides and some activation product nuclides such as 14$^{C}$ and 90$^{Sr}$ . In this study, the artificial neural network (ANN) method is suggested to improve the conventional SF determination methods - the LMA method and the regression method. The root mean squared errors (RMSE) of the ANN models are compared with those of the conventional SF determination models for 14$^{C}$ and 90$^{Sr}$ in two parts divided by a training part and a validation part. The SF determination models are arranged in the order of RMSEs as the following order: ANN model

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.223-226
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• 2004

The thesis examined the charactcri:stlC of pollutants exhausted from LNG facilities. So, combustion gas and concentration of greenhouse gas exhausted from gas boiler for home use, furnace facilities, electric power facilities, boiler for industrial use and boiler for heating fueled LNG is measured. And the exhaust factor of pollutants is produced by classify of pollutants in detail. And this exhaust factor is compared and investigated with data of a foreign nations.