• Journal of Wetlands Research
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• v.16 no.1
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• pp.11-18
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• 2014

The effect of elevated $CO_2$ and temperature on ecological characteristics of Cicuta virosa L., the endangered plant were examined under ambient $CO_2$+ambient temperature(AC-AT), ambient $CO_2$+elevated temperature(AC-ET) and elevated $CO_2$+elevated temperature for two years. Shoot length and the number of umbels were not different in three environmental gradients. The number of tillers was high in the order of EC-ET, AC-ET and AC-AT. The number of compound umbel was the lowest in the EC-ET. Fruit set rate was the highest in the AC-AT. These results mean that unsexual propagation of C. virosa may increase by promoting growth of tillers, rather than seed production under future global warming. This population growth study will be used as the important data for the research of Korean endangered species.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.138-142
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• 1996

The transition metal carbonylate, PPN+(${\eta}^5-MeCp)Mn(CO)_2Cl^-$ undergoes a novel ligand substitution reaction with PR3 (R=Me, Et, OEt, $C_6H_5$ in THF at elevated temperatures (40 $^{\circ}C$ up to 60 $^{\circ}C)$ under the pseudo-first-order reaction conditions (usually 20-fold excess of PR3 with respect to metal carbonylate concentrations) where chloride is displaced by PR3. The reaction follows overall first order dependence on [(${\eta}^5-MeCp)Mn(CO)_2Cl^-$]; however, the negative entropy changes of activation (${\Delta}S^{\neq}$=-19.3 e.u. for $P(OEt)_3$; ${\Delta}S^{\neq}$=-16.4 e.u. for $PPh_3$) suggest the existence of the intermediate, ((η3-MeCp)Mn(CO)2(THF)Cl-, which eventually transforms to the product (${\eta}^5-MeCp)Mn(CO)_2(PR_3)$.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.11
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• pp.733-738
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• 2008

Due to environmental concerns $CO_2$ has been reintroduced as a potential candidate to replace HFCs in refrigeration systems. Oils are always required in a vapor-compression cycle, and thus it is necessary to precisely estimate the thermodynamic mixture properties of $CO_2$-lubricant oil. In the present study, the density and the viscosity of the mixture was calculated by the Redlich and Kwong type EoS and the modified Peng and Robinson type viscosity EoS, respectively. The viscosity model was based on the similarity between P-v-T and T-$\mu$-P relationships. The predicted results were compared with the experimental data of Pens ado et al. whose test conditions were 100$\sim$650 bar of pressure and 303 K$\sim$353 K of temperature with the $CO_2$-POEs mixtures under 92.2 wt.% and 83.3 wt.% of $CO_2$ concentration. The mean deviations of the mixture density were 7.93% and 8.32% for 92.2 wt.% and 83.3 wt.% of $CO_2$ concentration, respectively. Concerning the viscosity, the mean deviations were 4% and 10% for 92.2 wt.% and 83.3 wt.% of $CO_2$ concentration under the Pensado et al.'s test conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.220-226
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• 2006

Soybean sprout is a traditional food and its market circulation as packed in a transparent film is increasing. To characterize the off-flavor produced from film-packed soybean sprouts, harvested soybean sprouts were stored at different temperature and oxygen conditions, and time-series changes in heads pace $O_2,\;CO_2$, ethanol (EtOH) concentrations as well as sensory off-flavor levels were measured. Lower temperature resulted in lower consumption of $O_2$, lower production of EtOH and less off-flavor. No off-flavors could be detected when atmospheric $O_2$ concentration was maintained over 4%, while alcoholic-flavor and off-flavor were initiated when $O_2$ decreased down to 2% and 1%, respectively. Under low $O_2$ conditions alcoholic-flavor following EtOH production preceeded prior to sensory off-flavor detection. Various aldehydes and fatty acids such as nonylaldehyde, decylaldehyde and stearic acid were identified by GC/MS from film-packed sprouts producing off-flavors. In conclusion to suppress off-flavor, soybean sprouts should be packed in a film which can control $O_2$ concentration over 2% and stored at low temperature around $4^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.40 no.8
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• pp.11-590
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• 1996

• YAKHAK HOEJI
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• v.32 no.3
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• pp.164-169
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• 1988

$^{13}C$ NMR chemical shifts for 18 ${\alpha}-susbstituted$ toluenes at high dilution in $CCl_4$ solution have been determined. Substituents are as follows: H, Me, Et, n-Pr, iso-Pr, Ph, F, Cl, Br, $NH_2$, NHMe, $NMe_2$, OH, OMe, OCOMe, $CO_2Me$, $CO_2Et$, CN. Those chemical shifts of the methylene carbon of the toluene and the ${\alpha}-carbon$ of the n-butane systems are correlated well. (r=.975, slope=.962)

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.62-68
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• 2010

This study was conducted to find out how the germination, phenology and leaf morphology of Phytolacca insularis(endemic species of Korea) and P. americana(alien species) react to the global warming situation. Seed and seedlings of two species were sampled and placed under two separate conditions for the experiment. One of the seed and seedlings was treated in the glass house with control(ambient $CO_2$+ambient temperature, (AC-AT), and the other with control(elevated $CO_2$+ elevated temperature, EC-ET), over the period of one year, 2008-2009. The germination rate of two species was fast, and the time of their germination started early, when they were treated at EC-ET than at AC-AT. Furthermore, the germination rate of Phytolacca insularis(endemic species of Korea) was found to be comparatively lower than that of P. americana(alien species). The former showed only vegetative growth whereas the latter showed both vegetative growth and reproductive growth in one year period. The more $CO_2$ degree and temperature increased, phenological responses of two species, including leaf growth, the formation of flower stems, flowering, and fruit maturing, became much faster, and the time of their leaf-yellowing was delayed. The lamina length of P. insularis was not significantly affected by elevated $CO_2$ and temperature. The lamina length of P. americana, on the other hand, became longer at EC-ET than at AC-AT, but the leaf width of both species increased at EC-ET. As for the number of leaves, both species showed no difference. Finally, the ratio of the leaf area of P. insularis was high at AC-AT, but P. americana was high at EC-ET. These results indicate that P. americana, aliens species, reacts more sensitively to global warming than P. insularis, endemic species, does.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.203-208
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• 2007

To develop a new whitening agent for cosmetics from natural products, Pimpinella brachcarpa was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. Crude ethanolic extract of P. brachycarpa and its four fractions-hexane, ethyl acetate(EtOAc), butanol and aqueous were evaluated for antioxidative effects and tyrosinase inhibitory activity. To elucidate the mechanism of active compounds of P. brachycarpa, we investigated the changes in protein level of tyrosinase, TRP-1 and TRP-2 using Western blotting and the changes in mRNA level of tyrosinase using RT-PCR technique. Following UV irradiation, expression of ET-1 in HaCaT keratinocytes was measured by quantitative enzyme immunoassay(EIA) using human ET-1 antibody. Crude ethanolic extract of P. brachycarpa and its four fractions-hexane, EtOAc, butanol and aqueous had free radical scavenging effect by 87.2, 2.5, 97.2, 80.5, 49.8% at 100 ${\mu}g/mL$ and tyrosinase inhibitory effect by 18.3, 15.1, 55.4, 13.1, 0 % at 100 ${\mu}g/mL$. P. brachycarpa EtOAc fraction significantly inhibited melanin production in B16 melanoma cells. Treatment with P. brachycarpa extract for 72 h suppressed the biosynthesis of melanin up to 58 % at 100 ${\mu}g/mL$. Especially, the EtOAc fraction of P. brachycarpa reduced the tyrosinase activity and tyrosinase expression in B16 melanoma cells in a dose-dependent manner. mRNA levels of tyrosinase and TRP-1 were markedly reduced by the EtOAc fraction of P. brachycarpa. Moreover, at the concentrations of $12.5{\sim}50{\mu}g/mL$ of the fraction, the production of UV-induced ET-1 in HaCaT keratinocytes(24 h after 8 $mJ/cm^2$ UVB irradiation) was reduced about 40%(p<0.05). P. brachycarpa could be used as a new natural skin-whitening agent due to the inhibitory effect of on melanin biosynthesis and endothelin-1 expression.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.87-95
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• 2001

대기중의 이산화탄소 농도는 산업화 이전에 275 ppm이었으나 매년 평균 1.0-1.5ppm씩 증가하여 1990년대에는 약 365 ppm이며(Conway et al., 1994), 다음 2000년대에는 약 두배에 달할 것으로 예측하였다(IPCC, 1990). 이산화탄소의 이러한 증가는 광합성의 재료로 사용되기 때문에(Bowes, 1991, Chen et al., 1997b) 작물의 생산성을 향산시킬 것이다(Bazzaz, 1990; Chen and Lenz, 1997). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.269-271
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• 1999

온실기체농도에 대한 감시는 전세계적으로 미국의 NOAA(National Oceanic and Atmospheric Administration)/CMDL(Climate Monitoring and Diagnostic Laboratories)의 관측망을 비롯하여 세계기상기구(WMO)의 지구대기감시(GAW)계획에 의하여 수행되고 있다(Keeling et al., 1976 ; Komhyr et al., 1989). 기상청에서는 온실기체의 관측을 위하여 1994년에 전남 무안의 무안기상대에 비분산적외선 이와 같이 측정된 $CO_2$농도자료가 배경대기관측자료로써의 신뢰를 받기 위해서는 적절한 질관리를 통하여 인간 및 생물의 활동에 의한 직접적인 영향 제거하여야 한다.(중략)