• Korean Journal of Agricultural Science
• /
• v.13 no.2
• /
• pp.279-288
• /
• 1986

One hundred and fifty one mutant strains were obtained from the parent strain Aspergillus oryzae MF by ultra-violet ray irradiation. Among those mutants a strain, Asp. oryzae UM-36 which hyperprodued protease, was selected and its morphological characteristics and the production of enzymes protease, ${\alpha}$-amylase, and glucoamylase on wheat bran koji and on soy-sauce koji were studied. The results obtained were as follows 1. The selected mutant showed slower growth and weak sporulation on malt agar and on Czapek agar than the parent strain. 2. The conidiophores of the mutant were generally shorter than those of the parent when grown on malt agar. 3. Sectoring in colonies was not found when grown on malt agar and on Czapek agar. 4. The level of protease production by the mutant was increased approximately 1,4-fold higher on wheat bran koji and 2-fold higher on soysauce koji than by the parent. 5. The production of ${\alpha}$-amylase and glucoamylase by the mutant were also increased as compared with the parent on wheat bran koji and on soy sauce koji. 6. In the case of parent strain and mutant strain, the highest activity of protease appeared after three days in wheat bran medium at $30^{\circ}C$ incubation, but the highest activities of ${\alpha}$-amylase and glucoamylase appeared after two days.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.6 no.4 s.23
• /
• pp.37-47
• /
• 2006

Urban development results in increased runoff volume and flowrates and shortening in time of concentration, which may cause frequent flooding downstream. Flow retardation structures to limit adverse downstream effects of urban storm runoff are used. There are various types of flow retardation measures include detention basins, retention basins, and infiltration basins. In basic planning phase, a number of planning models of detention ponds which decide storage volume by putting main variables were used to design detention ponds. The characteristics of hydrological parameters $\alpha,\;\gamma$ which are used in planning models of detention pond were analyzed. In this study, detention ponds data of Disaster Impact Assessment report at 22 sites were analyzed in order to investigate correlation between characteristic of urban drainage basin parameter and characteristics of detention pond parameter due to urbanization effects. The results showed that storage volume was influenced by peak discharge ratio $\alpha$ more than runoff coefficient ratio $\beta$ and peak discharge ratio $\alpha$ was influenced by runoff coefficient ratio $\beta$ less than regional parameter n. Storage ratio was mainly influenced by duration of design rainfall in the case of trapezoidal inflow hydrograph such as Donahue et al. method.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.43 no.4
• /
• pp.337-347
• /
• 2017

In this study, free radical scavenging activity and enzyme-linked immunosorbent assay (ELISA) experiments were carried out using Dioscorea japonica (D. japonica) and Chenopodium album (C. album) extracts to evaluate their anti-oxidative and anti-inflammatory effects. In the free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity, $EC_{50}$ of D. japonica and C. album were measured as 2.386 and 0.524 mg/mL, respectively. The free radical scavenging activity of the mixed sample of D. japonica and C. album was the highest when the D. japonica and C. album ratio was 2 : 1. The IL-6 and $TNF-{\alpha}$ ELISA assay showed that IL-6 in mouse spleen cells treated 1 mg/mL of samples, D. japonica and C. album decreased the production of IL-6 concentration by 27.17%, 72.30%. In the case of $TNF-{\alpha}$, D. japonica and C. album decreased 61.97% and 77.85% of $TNF-{\alpha}$ production, respectively. Through these results, we confirmed that D. japonica and C. album have antioxidant and anti - inflammatory effects and could be applied to natural medicine cosmetic having anti - inflammatory effects.

• Journal of Life Science
• /
• v.24 no.9
• /
• pp.1006-1011
• /
• 2014

Ginseng has been known to be highly effective for health as a traditional medicinal herb. Ginseng berry, or fruit of ginseng, contains ginsenoside, saponin, polyphenol, polyacetylene, alkaloid, etc. as the main compounds as does ginseng. The aim of this study is to evaluate any effect of ginseng berry water extract (GBE) on diabetic-associated molecules, such as enzymes, which are responsible for the glucose entry of the cells and the insulin receptor signaling molecules using HepG2 cells. Therefore, two enzymes, ${\alpha}$-amylase and ${\alpha}$-glucosidase, were selected and assayed for their activities in the presence of GBE in vitro. These two enzymes are responsible for producing glucose from dietary starch. Protein-tyrosine phosphatase 1B (PTP1B) and Akt1 are key proteins in the insulin receptor signaling pathway. These two intracellular signaling molecules were investigated for their expression levels in HepG2 cells after insulin and GBE treatment. GBE, at concentrations up to $1,000{\mu}g/ml$, did not exert any inhibitory effect on ${\alpha}$-amylase and ${\alpha}$-glucosidase. It was observed that the expression level of PTP1B was increased by insulin and the $25{\mu}g/ml$ GBE treatment enhanced the PTP1B level. However, GBE at a concentration of $200{\mu}g/ml$ reduced the expression level of PTP1B. In the case of Akt1, the Akt1 level by insulin was decreased by GBE treatment. These data suggest that the water extracts of ginseng berry have an influence on intracellular signaling by insulin.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.22 no.6
• /
• pp.387-396
• /
• 2010

A 3-D numeric model for the confined transient flow under sea ground have been developed. This is FDM model using Gauss-Seidel SOR (successive over-relaxation). This model shows the similar head distribution pattern to Theis analytic solution and MODFLOW simulation. The input flowrate to the aquifer and discharge of well have been compared. And it have been found that mass balance is influenced by the weight factor ${\alpha}$, i.e. fullyimplicit method (${\alpha}$=1) shows 5% error, but when ${\alpha}$ becomes to 0.5(Crank and Nicolson method) the mass balance becomes worse and the model result diverges. And the convergency of the model is not much different when $\lambda$ (over-relaxation factor)=0.8~1.5, but when $\lambda$>1.5, the model result diverges. The test-run shows that the well discharge becomes smaller when another well is near. This model can cover the isotropy$(Kx{\neq}Ky{\neq}Kz)$ and inhomogeneity, and can be used for the selection of well site, discharge calculation, and head prediction in case of the artificial recharge etc.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.38 no.12
• /
• pp.1009-1015
• /
• 2014

The present study investigated the effects of non-equilibrium condensation with the angle of attack on the coefficients of pressure, lift, and drag in the transonic 2-D flow of NACA0012 by numerical analysis of the total variation diminishing (TVD) scheme. At $T_0=298k$ and ${\alpha}=3^{\circ}$, the lift coefficients for $M_{\infty}=0.78$ and 0.81 decreased monotonically with increasing ${\Phi}_0$. In contrast, for $M_{\infty}$ corresponding to the Mach number of the force break, $C_L$ increased with ${\Phi}_0$. For ${\alpha}=3^{\circ}$ and ${\Phi}_0=0%$, $C_D$ increased markedly as $M_{\infty}$ increased. However, at ${\Phi}_0=60%$ and ${\alpha}=3^{\circ}$, which corresponded to the case of the condensation having a large influence, $C_D$ increased slightly as $M_{\infty}$ increased. The decrease in profile drag by non-equilibrium condensation grew as the angle of attack and stagnation relative humidity increased for the same free stream transonic Mach number. At ${\Phi}_0=0%$, the coefficient of the wave drag increased with the attack angle and free stream Mach number. When ${\Phi}_0$ > 50%, the coefficient of the wave drag decreased as ${\alpha}$ and $M_{\infty}$ increased. Lowering ${\Phi}_0$ and increasing $M_{\infty}$ increased the maximum Mach number.

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.603-610
• /
• 2001

The quality characteristics of soy yogurt prepared with different proteolytic enzymes and starter culture were evaluated. In order to facilitate the growth of lactic acid bacteria and subsequent production of lactic acid, soy protein isolate(SPI) was hydrolyzed using three kinds of proteases; one extracted from Aspergillus oryzae, bromelain and ${\alpha}-chymotrypsin$. The cultural systems employed thereafter for lactic fermentations were: 1) Bifidobacterium bifidum, 2) B. bifidum and Lactobacillus acidophilus, 3) B. bifidum and Lactobacillus bulgaricus. In soy yogurt, pH was more decreased by mixed culture method than single culture method with the accumulation of lactic acid. Viable cells of lactic acid bacteria in soy yogurts were measured $10^8$ CFU/g by the single culture method while $10^9$ CFU/g by the mixed culture method except ${\alpha}-chymotrypsin$ treatment. The amount of free amino acids in soy yogurts were substaintially increased by enzyme treatment. Viscosity was decreased by enzyme treatment, resulting in higher viscosity by ${\alpha}-chymotrypsin$ treatment. Water holding capacity was found to be higher in the single culture method in case of enzyme treatment. Among the various volatile flavor components isolated and identified after enzyme hydrolysis, acetaldehyde, ethanol, diacetyl, butyl alcohol contents tended to increase by lactic fermentation.

• Bulletin of the Korean Mathematical Society
• /
• v.44 no.3
• /
• pp.517-522
• /
• 2007

In this paper we consider the hyponormality of Toeplitz operators $T_\varphi$ on the Bergman space $L_\alpha^2(\mathbb{D})$ with symbol in the case of function $f+\bar{g}$ with polynomials f and g. We present some necessary conditions for the hyponormality of $T_\varphi$ under certain assumptions about the coefficients of $\varphi$.

• Communications for Statistical Applications and Methods
• /
• v.4 no.1
• /
• pp.207-218
• /
• 1997

We consider two models for the growth of population with overlaping generations. First, the model we will describe is basically the model given by Leslie(1945). This is only a one-sex model of population age structure and growth. Next, we introduce a model in which couples must be formed before reproduction occurs. If the maximum number of couples is formed, and if the couples are only formed from fermales of age x-a and males of age x at time t, $\alpha$ > 0. Then, we will solve the renewal equations for the reproductive value.

• Proceedings of the Safety Management and Science Conference
• /
• 2005.05a
• /
• pp.399-415
• /
• 2005

1991년 6월 신규 계면활성제 [${\alpha}-SF$]의 제조 공정의 하나인 메탄올 정류탑에 있어서 폭발사고가 발생했다. 폭발 형태는 ${\ulcorner}$폭굉${\lrcorner}$ 이였다 라고 판단되어지고 정류탑은 대파되었으며 탑벽 파편은 대강 900m 범위로 비산되었고 사망자 2명, 부상자 13명의 피해를 입었다. 원인물질은 계면활성제의 표백으로 사용하는 메탄올과 과산화수소에 의해 미량 생성한 유기과산화물(Metal Hydroperoxide)에서 정류탑의 운전정지과정 중에 공급액의 $0.1\%$부터 수십$\%$까지 국부적으로 농축되어져 열 폭발을 일으킨 것으로 추정 되어진다.