• International Journal of Highway Engineering
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• v.16 no.2
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• pp.19-24
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• 2014

PURPOSES : The study objective was to evaluate rheology and physical properties of SBS-modified warm-mix asphalt (WMA) binders in comparison with hot-mix asphalt (HMA) binders. METHODS : Four different SBS polymers were used to prepare polymer-modified asphalt (PMA) binders, and three different warm-mix additives (WAD) were used to prepare a total of 12 WMA PMA binders. The kinematic viscosity was measured at 115, $135^{\circ}C$. The PG was determined using DSR and BBR. The pass/fail (P/F) temperatures for high and low PG grading were evaluated for HMA PMA and WMA PMA binders. RESULTS : PG 76-22 binders could be prepared by modifying the base binder (PG 64-22) using 4.5 wt% of SBS. The kinematic viscosity (KV) of SBS PMA was increased by 3 times higher than that of base asphalt. The SBS PMA with WAD showed 10% lower KV than that of the normal SBS PMA at $115^{\circ}C$ The high P/F temperatures showed almost no difference between HMA PMA and WMA PMA binders. The high P/F temperature showed very high correlations with KV ($R^2$ > 0.97). The result of SBS modification caused increase of low P/F temperature by $2.7^{\circ}C$ on average. CONCLUSIONS : Since the PMA with WAD showed 10% lower KV than normal (HMA) PMA at $115^{\circ}C$, reducing PMA mixture temperature down to a WMA level was possible in this study. The higher KV binders showed the higher P/F temperature. There was almost no change in high P/F temperature due to the use of WAD. The SBS PMA, showing an increased low P/F temperature, might show somewhat poorer performance at low-temperature, even though the lower PG grade was staying at the same level, i.e., $-22^{\circ}C$.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.428.2-428.2
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• 2002

The present study was performed to examine the effects of oral administrations of Panax ginseng(PG) and P. quinquefolium(PQ) roots on hemodynamics and body temperature in healthy young men, since it was claimed that PG raises heat whereas PQ lowers heat by some ethnopharmacologists. The 42 healthy young male volunteers were divided into live groups. which were treated with mineral water(control), each high (9.0 g) and low (4.5 g) dose of PG and PQ. (omitted)

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.1-12
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• 2004

This study evaluated the asphalt binder characteristics for the hot-recycled asphalt mixture in which RAP was added in ambient temperature for surface course as well as for base course. RAPs were collected from four sources and their physical properties were evaluated. Mix designs were performed using 10 and 20% RAP contents for surface courses and 10, 20 and 30% for base courses. A virgin asphalt with the penetration grade of 60-80 was used for mixing recycled mixtures. Physical properties of recycled binders, including penetration, absolute viscosity, GPC, BBR and penetration after TFO were measured. From the results, regression analysis of absolute viscosity versus LMS in GPC showed $R^2$ being over 0.95, showing that GPC results estimate the absolute viscosity with relative accuracy. In BBR test, the resistance of recycled mixtures at low service temperature was inferior to the control, because the low temperature PG of recycled binder was one grade higher than that of the control binder.

• Food Science and Preservation
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• v.16 no.6
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• pp.804-809
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• 2009

Recently, many Koreans have started to consume aged kimchi fermented long-term at low temperatures. In the present study, the effect of low temperature ($5^{\circ}C$) on pH, titratable acidity (TA), organic acid level, viable microbial cell count, amino acid concentration, and polygalacturonase activity (PG) during long-term fermentation (46 weeks) of kimchi, were evaluated. After 10 weeks of fermentation, kimchi had a pH of 4.1 and a TA of 1.0%, respectively after 46 weeks fermentation, these values were 3.9 and 1.3%, respectively. Lactic acid, the ratio of lactic acid to acetic acid, and the ratio of Lactobacillus species/Leuconostoc species in kimchi increased as fermentation progressed from 10 weeks to 46 weeks. However, total viable cell counts of aerobic bacteria, yeasts, Lactobacillus species, and Leuconostoc species, free amino acid levels, and PG decreased as the fermentation period was extended from 10 weeks to 46 weeks.

• Proceedings of the Ginseng society Conference
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• 1980.09a
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• pp.151-170
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• 1980

Physiological response of Panax ginseng var. atropurpureacaulo (purple stem variety, Pg) to light was reviewed through old literatures and recent experiments. Canopy structure, growth, pigment, leaf anatomy, disease occurence, transpiration, photosynthesis (PS), leaf saponin, photoperiodism and nutrient uptake were concerned. P. ginseng var. xanthocarpus (yellow berry variety, Px) and Panax quinquefolius(Pq) were compared with Pg if possible. Compensation point(Cp) increased with increase of light and ranged from 110 to 150 at $20^{\circ}C$ but from 140 to 220 at $30^{\circ}C$ with 4 to 15 Klux indicating occurence of light and temperature-dependent high photorespiration. Characteristics of Korea ginseng to hate high temperature was well accordance with an observation 2000 years ago. Korea ginseng showed lower Cp and appeared to be more tolerant to high light intensity and temperature than American sheng although the latter showed greater PS, stomata frequency and conductance, chlorophyll and carotenoids. Px showed lower PS than Pg probably due to higher Cp. Total leaf saponin was higher in leaves grown under high light. Ratio or diol saponin and triol saponin(PT/PD) decreased with increase of light intensity during growing mainly due to decrease of ginsenoside $Rg_1$ but increase of ginsenoside Rd. Leaves of Pg and Px had $Rg_1$ but no $Rb_3$ which was only found as much as $20\%$ of total in Pq leaves, and decreased with increase of light intensity. Re increased in Pg and Px but decreased in Pq with increase of light. PT/PD in leaf ranged 1.0-1.5 in Pg and Px but around 0.5 in Pq. Korea ginseng has Yang characteristics(tolerant to high light and temperature), cultured under Eum(shade) condition and long been used for Yang efficacy (to build up energy) while Pq was quite contrary. Traditional low light $intensity(3-8\%)$ for Korea ginseng culture appeared to be strongly related to historical unique quality. Effect of light quality and photoperiodism was not well known. Experiences are long but scientific knowledge is short for production and quality assessment of ginseng. Recent scientific knowledge of ginseng should learn wisdom from old experiences.

• Journal of Plant Biotechnology
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• v.50
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• pp.225-231
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• 2023

Cold stress is one of the most vulnerable environmental stresses that affect plant growth and crop yields. With the recent advancements in genetic approaches using Arabidopsis and other model systems, genes involved in cold-stress response have been identified and the key cold signaling factors have been characterized. Exposure to low-temperature stress triggers the activation of a set of genes known as cold regulatory (COR) genes. This activation process plays a crucial role in enhancing the resistance of plants to cold and freezing stress. The inducer of the C-repeatbinding factor (CBF) expression 1-CBF module (ICE1-CBF module) is a key cold signaling pathway regulator that enhances the expression of downstream COR genes; however, this signaling module in Panax ginseng remains elusive. Here, we identified cold-signaling-related genes, PgCBF1, PgCBF3, and PgICE1 and conducted functional genomic analysis with a heterologous system. We confirmed that the overexpression of cold- PgCBF3 in the cbf1/2/3 triple Arabidopsis mutant compensated for the cold stress-induced deficiency of COR15A and salt-stress tolerance. In addition, nuclearlocalized PgICE1 has evolutionarily conserved phosphorylation sites that are modulated by brassinsteroid insensitive 2 (PgBIN2) and sucrose non-fermenting 1 (SNF1)-related protein kinase 3 (PgSnRK3), with which it physically interacted in a yeast two-hybrid assay. Overall, our data reveal that the regulators identified in our study, PgICE1 and PgCBFs, are evolutionarily conserved in the P. ginseng genome and are functionally involved in cold and abiotic stress responses.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.296-303
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• 2010

A peroxiredoxin cDNA (PgPrx) was isolated and characterized from the leaves of Panax ginseng. The cDNA is 716 nucleotides long and has an open reading frame of 489 base pairs with a deduced amino acid sequence of 162 residues. The calculated molecular mass of the mature protein is approximately 17.4 kDa with a predicted isoelectric point of 5.37. A GenBank BlastX search revealed that the deduced amino acid sequence of PgPrx shares a high degree homology with type II peroxiredoxin (Prx) proteins in other plants. The PgPrx gene was highly expressed in leaves, and expressed at a low level in the stem. To analyze the gene expression of PgPrx in response to various abiotic stresses, we utilized real-time quantitative RT-PCR. Our results reveal that PgPrx expression is induced by ultraviolet irradiation, low temperature, and salt. The induction of PgPrx in response to abiotic stimuli suggests that ginseng Prx may function to protect the host against environmental stresses.

• International Journal of Highway Engineering
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• v.15 no.1
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• pp.87-94
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• 2013

PURPOSES: To characterize the aging effect on asphalt binder, dynamic shear modulus mastercurve of two typical asphalt binders are developed. METHODS: To develop dynamic shear modulus mastercurve, dynamic shear modulus at high temperature and creep stiffness at low temperature are measured by temperature sweep test and bending beam rheometer test, respectively. RESULTS: It is observed that the aging effect on asphalt binder can be clearly observed from dynamic shear modulus mastercurve and the mastercurve can be utilized to predict behavior of asphalt binder at wide range of temperature. CONCLUSIONS: It is confirmed that SBS 5% modified binder has more desirable mechanical property at low and high temperature as a pavement material comparing to PG64-22 binder and the mastercurve is an effective tool to evaluate the property of asphalt binder.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.548-561
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• 2015

Atmospheric concentrations of polychlorinated dibezo-p-dioxins and furans (PCDD/Fs) were investigated at urban-residential (Group I: Suwon, Guri and Goyang), industrial (Group II: Ansan, Siheung and Bucheon), urban-rural mixed (Group III: Yangju, Pocheon and Dongducheon) and rural regions (Group IV: Yangpyeong) in Gyeonggi-do from February 2012 to November 2012 quarterly. The concentrations of PCDD/Fs ranged from 0.018 to $0.109pgTEQm^{-3}$ in Group I (mean value: $0.061pgTEQm^{-3}$), 0.059 to $0.367pgTEQm^{-3}$ in Group II (mean value: $0.179pgTEQm^{-3}$), 0.072 to $0.836pgTEQm^{-3}$ in Group III (mean value: $0.334pgTEQm^{-3}$) and 0.014 to $0.066pgTEQm^{-3}$ in Group IV (mean value: $0.034pgTEQm^{-3}$), respectively. In spite of the less PCDD/F emission sources than Group II (industrial regions), the level of PCDD/Fs in urban-rural mixed area showed the highest values with high fluctuation. It's likely that the Group III was affected by fugitive emissions such like biomass burning and unregulated open burning. The mean contribution of particle phase to total PCDD/F concentration was above 83% because most of PCDD/F congeners were partitioned into particle phase. We evaluated their gas-to-particles equilibriums with the regression between the particle-gas partition coefficient, $K_P(m^3{\mu}g^{-1})$ and corresponding subcooled liquid vapor pressure ($P_L$). The logarithm-$K_P$ of PCDD/Fs was poorly correlated with $P_L$ at low ambient temperature (below $10^{\circ}C$) and the slope (m) values for log-log plots of the $K_P$ vs. $P_L$ was steeper in the Group 2 and Group 3 than residential area. It implies that the slope values were likely influenced by both the direct emission source of PCDD/Fs and ambient temperature.

• Elastomers and Composites
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• v.57 no.4
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• pp.222-230
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• 2022

In this study, a low-heat additive with a crosslink structure was dispersed in asphalt to simultaneously lower the production temperature of, and to modify the asphalt binder. This low-heat additive was prepared by different feeding ratios of styrene-butadiene-styrene (SBS) and polyvinylchloride (PVC) as polymer modifiers, and ZnO as a crosslinking agent. In order to confirm the crosslinking density and compatibility of the crosslink structured low-heat additive with asphalt, surface free energy, swelling ratio, differential scanning calorimetry (DSC), and scanning electron microscope (SEM) parameters were carefully investigated to examine this relationship, and the role of the crosslink structured low-heat additive. In addition, by measuring the penetration and softening point of the asphalt binder, it was confirmed that it corresponds to PG 64-22. With increasing ZnO in the crosslink structured low-heat additive, the swelling ratio decreased, leading to an increase in crosslinking density. The crosslink structured low-heat additive and the asphalt binder were found to be compatible with each other by DSC and SEM analysis.