• Journal of Ginseng Research
• /
• v.18 no.3
• /
• pp.196-199
• /
• 1994

A study was designed to investigate the sorption characteristics of binary mixture of red ginseng powder and maltodextrin(DE-17) or lactose stored at various relative humidities ranging from 52% to 93%. At low relative humilities below RH 67%, the sorption equilibrium was easily achieved, whereas at higher relative humidity values over 75%, all of the mixtures tended to absorb moisture continuously with an increase in storage time. A linear equation of log(dw/dt): a log(t)+ log b was found to be valid between the sorption rate and storage time with respect to storage humilities. A linearity was also found between log(1-Aw) and the amount of water absorbed over the Aw range of 0.52∼0.93 and the slope was affected by the kind of sugar added with that of red ginseng powder and maltodextrin mixture being the smallest.

• The Pure and Applied Mathematics
• /
• v.10 no.3
• /
• pp.185-192
• /
• 2003

It is shown that every almost linear mapping $h{\;}:{\;}X{\;}{\rightarrow}{\;}Y$ of a complex normed space X to a complex normed space Y is a linen. mapping when h(rx) = rh(x) (r > 0,$r\;{\neq}\;1$$x{\;}{\in}{\;}X$, that every almost quadratic mapping $h{\;}:{\;}X{\;}{\rightarrow}{\;}Y$ of a complex normed space X to a complex normed space Y is a quadratic mapping when $h(rx){\;}={\;}r^2h(x){\;}(r{\;}>{\;}0,r\;{\neq}\;1)$ holds for all $x{\;}{\in}{\;}X$, and that every almost cubic mapping $h{\;}:{\;}X{\;}{\rightarrow}{\;}Y$ of a complex normed space X to a complex normed space Y is a cubic mapping when $h(rx){\;}={\;}r^3h(x){\;}(r{\;}>{\;}0,r\;{\neq}\;1)$ holds for all $x{\;}{\in}{\;}X$.

• Bulletin of the Korean Mathematical Society
• /
• v.56 no.5
• /
• pp.1117-1127
• /
• 2019

Let ${\mathcal{L}}_2=(-{\Delta})^2+V^2$ be the $Schr{\ddot{o}}dinger$ type operator, where nonnegative potential V belongs to the reverse $H{\ddot{o}}lder$ class $RH_s$, s > n/2. In this paper, we consider the operator $T_{{\alpha},{\beta}}=V^{2{\alpha}}{\mathcal{L}}^{-{\beta}}_2$ and its conjugate $T^*_{{\alpha},{\beta}}$, where $0<{\alpha}{\leq}{\beta}{\leq}1$. We establish the $(L^p,\;L^q)$-boundedness of operator $T_{{\alpha},{\beta}}$ and $T^*_{{\alpha},{\beta}}$, respectively, we also show that $T_{{\alpha},{\beta}}$ is bounded from Hardy type space $H^1_{L_2}({\mathbb{R}}^n)$ into $L^{p_2}({\mathbb{R}}^n)$ and $T^*_{{\alpha},{\beta}}$ is bounded from $L^{p_1}({\mathbb{R}}^n)$ into BMO type space $BMO_{{\mathcal{L}}1}({\mathbb{R}}^n)$, where $p_1={\frac{n}{4({\beta}-{\alpha})}}$, $p_2={\frac{n}{n-4({\beta}-{\alpha})}}$.

• Bulletin of the Korean Mathematical Society
• /
• v.59 no.5
• /
• pp.1255-1268
• /
• 2022

We consider the Schrödinger type operator 𝓛 = (-𝚫_ℍⁿ)² + V² on the Heisenberg group ℍⁿ, where 𝚫_ℍⁿ is the sub-Laplacian and the non-negative potential V belongs to the reverse Hölder class RH_s for s ≥ Q/2 and Q ≥ 6. We shall establish the (L^p, L^q) estimates for the Riesz transforms T_𝛼,𝛽,j = V^2𝛼𝛁^j_ℍⁿ𝓛^-𝛽, j = 0, 1, 2, 3, where 𝛁_ℍⁿ is the gradient operator on ℍⁿ, 0 < α ≤ 1-j/4, j/4 < 𝛽 ≤ 1, and 𝛽 - 𝛼 ≥ j/4.

• Korean Journal of Veterinary Research
• /
• v.39 no.6
• /
• pp.1151-1160
• /
• 1999

This study was conducted to detect the toxoplasma-specific DNA in peripheral blood collected from cats experimentally infected with Toxoplasma gondii (RH strain) and from domiciled cats by B1 gene-base polymerise chain reaction(PCR). The sensitivity of oligonucleotide primer, T-1 & T-2, designed from toxoplasma B1 gene amplification method was compared with parasite detection by mouse inoculation(MI). And also, latex agglutination test(LAT) and indirect fluorescent antibody test(IFAT) were conducted to detect the fluctuation of serum antibodies compared with the detection of toxoplasma by PCR and MI. Toxoplasma B1 gene PCR was shown consistently high sensitivity and the results obtained by PCR agreed completely with those from MI. All blood samples collected before infection with T gondii gave negative results by PCR and MI. Also, toxoplasma Bl gene PCR was not cross reaction with Neospora caninum DNA and normal cat leucocyte as controls. The toxoplasma-specific DNA was detected by PCR in blood of 5 cats experimentally infected with T gondii 6 days after infection and the detection of this specific-DNA was long lasted in blood for 64 days after infection. The detection of toxoplasma-specific DNA by PCR could be identified as few as 10 tachyzoites and the isolation of T gondii by MI could be isolated as few as 1 tachyzoite from tenfold serial dilution of T gondii with normal cat blood, respectively. In healthy domiciled cats, the toxoplasma-specific DNA and the parasite were detected and isolated in blood from 3 of 56(5.3%) cats by both PCR and MI, respectively. In the results of antibody test from the total 56 heads of healthy domiciled cats, the positive rates are 15(26.7%) by LAT and 19(33.9%) by IFAT. These results suggest that PCR detection of toxoplasma can be applied as a sensitive and specific diagnostic and research tool.

• Clean Technology
• /
• v.25 no.1
• /
• pp.46-55
• /
• 2019

CdS and CdZnS/ZnO materials were prepared using precipitation method and used as photocatalysts for the photocatalytic degradation of rhodamine B (RhB) under visible light irradiation. The prepared photocatalysts were also characterized by XRD and UV-vis DRS. The results indicated that the photocatalysts with intended crystalline structures were successfully obtained and both the CdS and CdZnS/ZnO can absorb visible light as well as UV. The photocatalytic activities were examined with the addition of scavenger for various active chemical species and the difference of reaction mechanisms over the catalysts were discussed. The $CH_3OH$, KI and p-benzoquinone were used as scavengers for ${\cdot}OH$ radical, photogenerated positive hole and ${\cdot}O_2{^-}$ radical, respectively. The CdS and CdZnS/ZnO showed different photocatalytic degradation mechanisms of RhB. It can be postulated that ${\cdot}O_2{^-}$ radical is the main active species for the reaction over CdS photocatalyst, while the photogenerated positive hole for CdZnS/ZnO photocatalyst. As a result, the predominant reaction pathways over CdS and CdZnS/ZnO photocatalysts were found to be the dealkylation of chromophore skeleton and the cleavage of the conjugated chromophore structure, respectively. The above results may be mainly ascribed to the difference of band edge potential of conduction and valence bands in CdS, CdZnS and ZnO semiconductors and the redox potentials for formation of active chemical species.

• Korean Journal of Food Science and Technology
• /
• v.38 no.4
• /
• pp.521-525
• /
• 2006

Korean ginseng was heat treated at various temperatures (110, 120, 130, 140 and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr). The heat treated ginseng extract was analyzed for the total polyphenol content, total flavonoid content, DPPH free-radical scavenging, 5-HMF and ginsenoside. The total phenolics and flavonoid content increased with increasing treatment temperature and time. The highest total phenolics content was 29.46 mg/g (d.b) in $150^{\circ}C$ for 1hr (control: 2.68 mg/g). The highest total flavonoid content was 4.75mg/g (d.b) in $150^{\circ}C$ for 2hr (control: 0.39 mg/g). The antioxidant activity increased until $140^{\circ}C$ for 3 hours. An extension of the treatment time did not have any effect, and the antioxidant activity decreased at temperatures higher than $150^{\circ}C$ for more than 2 hours. The content of ginsenoside $Rg_1$, Re, $Rb_2$ and Rb3 rapidly decreased with increasing treatment temperature and time. Ginsenoside $Rg_3$ and $Rh_2$ were newly produced, or their contents increased with increasing treatment temperature and time.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.21 no.1
• /
• pp.125-131
• /
• 1976

To study the effects of temperature, day length, and various plant growth regulator treatments on the tuber formation of Irish cobbler, this experiment was carried out with 2 combinations of day-length and temperature and 11 kinds of growth regulator, including GA, and their combinations. For the tuber formation, low temperature-short day condition played decisive role, and exceeded the effects of growth regulators. 4 times foliar application of 10 ppm GA resulted marked elongation of stolon but did not inhibit the tuber formation even under high temperature longday condition.

• Resources Recycling
• /
• v.28 no.2
• /
• pp.46-53
• /
• 2019

In this study, the extraction and reduction behavior of platinum group metals in a non-aqueous solvent based on ionic liquids was investigated in order to confirm a new extraction technology of platinum group metals. Platinum was selectively extracted using an ionic liquid $[C_4mim]PF_6$ from a mixed solution of $PdCl_2$, $PtCl_4$ and $RhCl_3$ dissolved with concentration ratio of 10:1:0.5 M. After stripping of the metals by 1 M $HNO_3$ solution, the platinum was preferentially reduced by aqueous electrolysis on gold electrode at -0.8 V (vs. Pt-QRE). The residual palladium and rhodium were transferred to ionic liquid of $[C_4mim]Cl$. The metallic palladium and rhodium could be sequentially reduced on gold and STS304 as working electrodes by non-aqueous electrolysis, respectively.

• Resources Recycling
• /
• v.32 no.3
• /
• pp.45-56
• /
• 2023

This study analyzed the economic and environmental effect of recycling rhodium used in the non-catalytic field. As an analysis methodology, economic effect analysis applied cost-benefit analysis and resource-saving effect analysis and the environmental effect analysis applied life cycle assessment (LCA). The results show that from an economic point of view, the cost-benefit ratio was 1.28, which was feasible, and the cost reduction was 237,000 won based on 1 g of rhodium recycled and the amount of rhodium recycled was 7.17 billion won in 2025. As for the environmental effect, the greenhouse gas(GHG) emissions were compared between the case of recycling based on rhodium 1 kg and the case of overseas sales. The calculation results show that based on rhodium 1 kg, greenhouse gas emissions were reduced by 99.8%, from 65 kg CO₂eq./kg-Rh when recycling to 28,800 kg CO₂eq. when sold overseas. The results obtained from this study could suggest that rhodium recycling is necessary in Korea where resources are scarce by analyzing the economic and environmental effect of recycling rhodium used in the non-catalytic field.