• 대한수학회보
• /
• 제52권3호
• /
• pp.907-914
• /
• 2015

In this paper, we consider a viscoelastic plate equation with p-Laplacian $u^{{\prime}{\prime}}+{\Delta}^2u-div({\mid}{\nabla}u{\mid}^{p-2}{\nabla}u)+{\sigma}(t){\int}_{0}^{t}g(t-s){\Delta}u(s)ds-{\Delta}u^{\prime}=0$. By introducing suitable energy and Lyapunov functionals, we establish a general decay estimate for the energy, which depends on the behavior of both ${\sigma}$ and g.

• 자연과학논문집
• /
• 제5권1호
• /
• pp.1-3
• /
• 1992

G가 compact Lie 군이고 $\pi$ : $E to S^1$이 $S^1$ 상의 G-line bundle 일때, 군 작용이 없다면, 부드러운 trivial G-line bundle $E to S^1$ 은 S(V) $\times$ $\delta to S(V)$ 와 동치이고 부드러운 nontrivial G-line bundle $E to S^1$ 은 S(V) $\times$$z_2$ $\delta to S(V)$/$Z_2$=P(V)와 동치 이다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권8호
• /
• pp.1135-1140
• /
• 2005

Dogs are a very good indicator of the pollution load on the environment. They share people's environment and are exposed to the action of the same pollutants. This study was to estimate the heavy metal contents in dog hairs in domestic districts, and to assess effects of age, sex, feed habits, living area, breeding environment and smoking habit of owner. The mean concentrations of heavy metals in 204 samples were 0.09${\pm}$0.10 ${\mu}g$/g, 0.21${\pm}$0.09 ${\mu}g$/g, 0.82${\pm}$0.09 ${\mu}g$/g and 0.48${\pm}$0.07 ${\mu}g$/g (Cadmium (Cd), Mercury (Hg), Lead (Pb) and Chromium (Cr)) in dog hairs, respectively. Concentrations of Pb, Cd, Hg and Cr in dog hairs in Yeongnam including Ulsan and Seoul, were higher than in Chungchong and Honam, and concentrations of Pb were significantly different (p<0.01). Concentrations of Cd, Hg, Pb and Cr in dog hairs increased with age (p<0.05). Only dogs fed commercial pet foods had significantly higher Cd and Cr concentrations in hairs than dogs fed dog feed and human diet (p<0.01 in Cd and p<0.05 in Cr). Cr concentrations of dog hairsfrom dogs kept on cement floors were the highest of the other environments (p<0.01). Heavy metal concentrations of dogs owned by smokers, were higher than dogs of non-smokers, but there were no significant differences.

• 한국자원식물학회지
• /
• 제35권6호
• /
• pp.713-719
• /
• 2022

Platycodon grandiflorum and Glycyrrhiza uralensis contain several bioactive compounds, such as saponin, oleanolic acid, and flavone. P. grandiflorum and G. uralensis have traditionally been used to treat disorders related to blood pressure, diabetes, and counteracting poison, and they have antinociceptive and antiinflammatory properties. However, the validity of complex saponin's vasodilatory effect has not been scientifically investigated. Therefore, this study explores the vasodilatory effect of complex saponin extracted from P. grandiflorum and G. uralensis mixture extract on rabbit carotid arteries. To this end, arterial rings with intact or damaged endothelium were used in an organ bath experiment and contracted by endothelin. Complex saponins, the major active constituents of P. grandiflorum and G. uralensis mixture extract, exhibited a moderate vasodilatory effect on the rabbit's basilar arteries. Therefore, treatment with complex saponin extracted from P. grandiflorum and G. uralensis mixture extract may selectively accelerate cerebral blood flow through basilar arterial dilation. Overall, the findings suggest that the extracted complex saponins can serve as vasodilator sources.

• 한국미생물·생명공학회지
• /
• 제29권4호
• /
• pp.221-226
• /
• 2001

S. thermocyaneoviolaceus 가 생산하는 xylanases를 황산암모늄에 의한 염석 및 투석에 의해 조제한 효소를 이용하여 자일로오리고당을 생산하기 위한 최적 반응조건을 설정하였다. 자알로올리고당 생산을 위한 기질로는 oat spelt xyaln 보다 birchwood xylan을 사용하는 것이 더 좋았다. 반응온도의 영향을 조사한 결과 효소의 열 안정성과 자일로올리고당의 생선량 등을 고려할 때 $60^{\circ}C$에서 반응하는 것이 가장 좋았다 효소의 농도 pH의 영향및 반응시간의 영향을 조사한 결과 10 unit/ml xylanases를 첨가하여 pH 6.0에서 12 시간 반응시켰을 때 가장 많은 양의 자일로올리고당을 생산할 수 있었다. 이러한 최적 반응 조건에서 10% birchwood xylan 으로 부터 생산할 수 있는 자일로올리고당의 조성는 X2, X3, X4, X5 및 X6가 각각 20.1, 8.9 , 4.5, 16.2 및 9.1 g/I 이었으며 이때 생산되는 총 자일로올리고당 (X2~X6)은 58.8 g/I 이었다.

• The Korean Journal of Ecology
• /
• 제14권2호
• /
• pp.171-179
• /
• 1991

In this study, the balnce of the litter production and decompsition on the forest floors in the green belt nearby seoul, which had been established in 1972, and turnover cycles of minerral nutrients were inverstigated. litter production and decomposition in the forests of quercus accutissima, q, serrata, q. mongolica, salix koreensis and alnus hirsuta were reached at the equilibium stated from 1972 to 1988 but this balance in the pine forest of pinus densiflore and p. rigida was not. Under the forests in the blance of the litter production and decomposition, the maximum amounts of n, p, k, ca and na retured to soil annually were 4.9g/㎡ in the alnus hirsuta forest, 0.35g/㎡ in the salix koreensis forest, 2.70g/㎡ in the quercus accutissima forest, 8.85g/㎡ in the s. koreensis forest and 3.93g/㎡ in the s. koreensis forest, respectively, and the minimum were 2.8g/㎡ in the s. koreensis forest, 0.108g/㎡ in the q. mongolica forest, 0.06g/㎡ in the s. koreensis forest, 2.12g/㎡ q. mongolica forest and 0.15g/㎡ in the q.accutissima forest.

• Bulletin of the Korean Chemical Society
• /
• 제21권12호
• /
• pp.1202-1206
• /
• 2000

Transmission of substituent effects through 5-membered heteroaromatic rings is investigated theoretically at the RHF/6-31+G and B3LYP/6-31+G levels using the equilibria for the $OH^- addition to five-membered heteroaromatic aldehydes (5MHA). The transmission efficiency (S) in 5MHA(A) increases in the order NH>O>S>PH but the order exactly reverses in 5MHA($T^-$). This is originated by the delocalizability of the ${\pi}$ lonepair on Y, $$n_\pi$(Y)$. A better correlation is obtained with ${\sigma}_p^-$ in the Hammett plots with positive slope, $p_z$ > 0, indicating that the substituent (Z) effects are not transmitted by a direct conjugation. The magnitude of $p_z$ for Y=NH is the largest among the heteroaromatic systems, which is consistent with the largest transmission efficiency change $({\Delta}S)$. The equilibria for the addition processes are favorable in the gas phase $({\Delta}G^o<0)$, which reverses to unfavorable in aqueous solution $({\Delta}G^o>0)$ due to the relatively large salvation energy of $OH^-$ in the initial state in aqueous solution. The orders of ${\Delta}G^o$ and $p_z$ in the gas phase are almost maintained in solution.

• 현장농수산연구지
• /
• 제9권1호
• /
• pp.105-117
• /
• 2007

This study was carried to analyze the demonstrational cultivation process of selenium supplemented P. linteus and G. lucidum from 2005 to 2006 and ifs effect at Hochimin Agricultural Technology College(HATC) in Vietnam, according to the mutual contract between the Yunjung-nongwon, a fanning company in Korea and HATC. As a result of the demonstrational cultivation of selenium supplemented P. linteus and G. lucidum, the external aspect, such as size, thickness and color of the P. linteus and G. lucidum were very much high qualified comparing to the same strain P. linteus and G. lucidum generally cultivated in Korea. The major contribution factors to this high qualified mushroom product could be drawn as followings; keeping growing condition of the mushroom with precise data collection of Vietnam climate and weather, involvement of the various professors of Korea National Agricultural College(KNAC), maintenance of bio-technical security through the strain cultivation on the oak log in Korea, the Yunjung-nongwon manager's endeavor being consulted by the various professors of KNAC even to be a student of the agricultural chief executive officer(CEO) training course in KNAC and the HATC's constant cooperation to the mushroom demonstrational cultivation instead of the orchid which was originally contracted item.

• 충청수학회지
• /
• 제35권4호
• /
• pp.315-327
• /
• 2022

In this paper, we investigate the transferred superstability for the p-radical sine functional equation $$f\(\sqrt[p]{\frac{x^p+y^p}{2}}\)^2-f\(\sqrt[p]{\frac{x^p-y^p}{2}}\)^2=f(x)f(y)$$ from the p-radical functional equations: $$f({\sqrt[p]{x^p+y^p}})+f({\sqrt[p]{x^p-y^p}})={\lambda}g(x)g(y),\;\\f({\sqrt[p]{x^p+y^p}})+f({\sqrt[p]{x^p-y^p}})={\lambda}g(x)h(y),$$ where p is an odd positive integer, λ is a positive real number, and f is a complex valued function. Furthermore, the results are extended to Banach algebras. Therefore, the obtained result will be forced to the pre-results(p=1) for this type's equations, and will serve as a sample to apply it to the extension of the other known equations.

• 아시안잔디학회지
• /
• 제10권4호
• /
• pp.305-313
• /
• 1996

This study was carried out to investigate the removal rates of Cd and Pb of the litters in the Phragmites communis. Miscanthus sacchariflorus, Typha angustata, Scirpus tabernaemontani grassland aquatic ecosystem in the lake Paldangho. The annual production of Cd and Pb were 0.005g /$m^2$ , 0.21g /$m^2$in P. commumis, 0.004g /$m^2$, O.08g /$m^2$ in M. sacchariflorus, 0.023g /$m^2$, 0.42g /$m^2$ in T. angustata and 0.020g /$m^2$, 0.23g /$m^2$ in S. tabernaemontani respectively. The removal rates of Cd and Pb of the litters were 0.83, 0.85 in P. communis. 0.36, 0.54 in M. sacchariflorus, 0.61, 0.51 in T. angustata and 0.76, 0.71 in S. tabernaemontani, respectively. The times required to decay 50, 95, 99 percent of the steady state level and turnover values of cadmium on the grassland floor were 0.83, 3,60, 6.00 years in P. communis. 1.90, 8.24, 13.74 years in M.sacchariflorus, 1.15, 4.96, 8.27 years in T. angustata and 0.91, 3.95, 6.58 years in S. tabernaemontani The times required to decay 50, 95, 99 percent of the steady state level and turnover values of lead on the grassland floor were 0.81, 3.51, 5.86 years in P. communis. 1.28, 5.56, 9.26 years in M. sacchariflorus, 1.37, 5.94, 9.90 years in T. angustata and 0.97, 4.21, 7.02 years in S. tabernaemontani. Key words: Removal rate, Accumulation, Paldangho, Cadmium, Lead, Phragmites communis Miseanthus sacchariflorus, Typha angustata, Scirpus tabernaemontani.