• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.1
• /
• pp.72-84
• /
• 1993

This study was carried out to understand the varietal variation in physicochemical properties of rice grain and those environmental changes by different transplanting time, and to elucidate the interrelationships among the factors related with eating quality of cooked rice. Fifty three rice samples, among which fifty samples were harvested at ordinary or late transplanted plots of the Crop Experiment Station in Suwon and three samples were harvested orpurchased from Niigata prefecture in Japan, were tested for various physicochemical components of rice grain and some physical factors of cooked rice. All of twenty seven rice cultivars tested were the recent-bred Korean japonica rice showing the wide range of maturity from early to medium-late heading and considerable difference in palatability of cooked rice. Amylose content, taste value by Nireco palatability tester (TVN), iodine blue color of cooking extracts(IB), and the ratio of IB /extracted solid amounts (ES) increased significantly by late transplanting, while viscosity (VN) and Mg / K. N value by Nireco tester, hot-water absorption of milled rice (HA), loss tangent of cooked rice by Rheolograph-Micro(LT), and most viscogram characteristics except setback viscosity (C-P) decreased drastically by late transplanting as compared with ordinary transplanting. Most of physicochemical properties of milled rice revealed narrower varietal variation in lately transplanted plot than in ordinary transplanted one. Protein content (PRO), volume expansion rate of cooked rice(VE), C-P and all physical factors of cooked rice by Rheolograph-Micro showed almost negligible seasonal variation, while amylose content (AM), VN, HA, IB/ES, peak viscosity(P), hot viscosity(H) and breakdown(P-H) viscosity exhibited considerably large seasonal variation. The early-headed varieties revealed lower amylose content and smaller seasonal variation of IB/ES compared with medium or medium-late headed rice varieties. AM was closely associatied with IB and IB / ES and VN was highly correlated with Mg/K. N and TVN in both ordinary and late transplanted plots. VN also was highly negatively correlated with cooking characteristics and highly positively correlated with viscogram properties in ordinary culture. PRO was closely connected with moisture content of milled rice and L T in ordinary transplanted plot. IB, which was closely connected with ES, was also singificantly associated LT, P and P-H in ordinary seasonal culture. IB/ES was highly negatively correlated with P, P-Hand P-H / C-P in ordinary culture but with LT and dynamic viscosity of cooked rice in late seasonal culture. The thirty rice cultivars were largely classified into two varietal groups by cluster analysis with physicochemical properties related with eating quality of cooked rice. Korean and Japanese high-quality rice cultivars were separately distributed in two respective varietal group.

• Korean Journal of Food Science and Technology
• /
• v.2 no.2
• /
• pp.34-37
• /
• 1970

The variation of acidity, pH and oxidation-reduction potentials of Dongchimi (a kind of large raddish pickle) during its fermentation was investigated. Estimation of oxidation-reduction potentials was carried out by the electric method. 1. Acidity was increased-3.5% by lactic acid and pH was decreased 3.4 during Dongchimi fermentation. 2. In Dongchimi, oxidation-reduction potentials was comparatively high (rH above 10) in the earlier stage and then decreased rapidly from rH 15 to 2.0 but slightly increased rH 5.0 in the later stage of the fermentation. 3. It is suggested that the earlier stage of fermentation was more aerobic condition than the later stage.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1997.05a
• /
• pp.68-69
• /
• 1997

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.600-604
• /
• 2003

This study pointed at isolation of bunker-C oil degrading bacteria and then estimation of it's degrading capability in environmental conditions. Degradation ratio of the excellent isolate was appeared to 40.5% and 44.7% when the oil was treated to 1% and 5%, respectively. The isolate was identified to Acinetobater calcoaceticus SEBCM. In pH test, high degrading effect was appeared to about 73% at pH 6 and pH 7, and low degrading ratio was 37% at pH 4. Its growth condition at temperature has not large variation in $15^{\circ}C\;{\sim}30^{\circ}C$, Quantity of nitrogen for it's good growth was ranged of $0.5\;g/L{\sim}2\;g/L$. As these results, we realized that this isolate have good activity when treated to $15\;{\sim}30^{\circ}C$ of temperature and $6{\sim}7$ of pH.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.4
• /
• pp.390-393
• /
• 2005

N-nitrosodimethylamine (NDMA), a potent carcinogenic, has recently been observed at drinking water supply systems in USA and Canada. The NDMA formation was studied as a function of chloramine concentration (0.001-0.1 mM) at a fixed dimethylamine (DMA) concentration of 0.05 mM at different initial pH (6, 7, 8). It was found that the NDMA formation rate varied with pH values. The formation of NDMA increased with increasing chloramine concentration and showed maximum yields of 2.4% and 1.6% at pH 7 and 8, respectively. A good correlation ($r^2>0.99$) was observed between the molar ratio (chloramine/DMA) and NDMA formation at pH 7 and 8. Linearity of the NDMA formation appeared to be related to chloramine concentrations.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.4 no.2
• /
• pp.19-25
• /
• 1996

A fundamental study on composting garbage was performed in a laboratory scale of a high-speed composting reactor. Major parameters were moisture content, temperature and C/N ratio. The results are as follows; pH of the compost was the highest at moisture 60% and anaerobic condition occurred at 70%. It was, also, found that C/N ratio, caused a nitrogen loss due to an occurrence of plentiful $NH_3$. Under controlling Temperature, pH was the highest at $60^{\circ}C$ and an inverse effect for Composting occurred under excessive Temperature as pH at $70^{\circ}C$ was lower than that of soil. The variation of pH and C/N ratio was the lowest when C/N ratio was 25. The results obtained from composting garbage revealed that the best condition of composting occurred under 50 to 60% of moisture content, $60^{\circ}C$ of temperature, and 25 of C/N ratio. It is believed that composting may be finished with in 56 hours if an optimal condition is setting up.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.5
• /
• pp.712-720
• /
• 2007

To investigate clonal variations of recombinant Chinese hamster ovary(rCHO) clones in response to culture pH and temperature, serum-free suspension cultures of two antibody-producing CHO clones(clones A and B), which were isolated from the same parental clone by the limiting dilution method, were performed in a bioreactor at pH values in the range of 6.8-7.6, and two different temperatures, $33^{\circ}C\;and\;37^{\circ}C$. In regard to cell growth, clone A and clone B displayed similar responses to temperature, although their degree of response differed. In contrast, clones A and B displayed different responses to temperature in regard to antibody production. In the case of clone A, no significant increase in maximum antibody concentration was achieved by lowering the culture temperature. The maximum antibody concentration obtained at $33^{\circ}C$(pH 7.4) and $37^{\circ}C$(pH 7.0) were $82.0{\pm}2.6$ and $73.2{\pm}4.1{\mu}g/ml$, respectively. On the other hand, in the case of clone B, an approximately 2.5-fold increase in maximum antibody concentration was achieved by lowering the culture temperature. The enhanced maximum antibody concentration of clone B at $33^{\circ}C$($132.6{\pm}14.9{\mu}g/ml$ at pH 7.2) was due to not only enhanced specific antibody productivity but also to prolonged culture longevity. At $33^{\circ}C$, the culture longevity of clone A also improved, but not as much as that of clone B. Taken together, CHO clones derived from the same parental clone displayed quite different responses to culture temperature and pH with regards antibody production, suggesting that environmental parameters such as temperature and pH should be optimized for each CHO clone.

• Journal of Korean Society on Water Environment
• /
• v.28 no.4
• /
• pp.551-560
• /
• 2012

The objectives of this study were to elucidate spatio-temporal heterogeneity of water chemistry and develop empirical models using trophic variables in Daechung Reservoir during 2005-2010 along with in situ tests of nutrient enrichment bioassays (NEB). The relations of water quality parameters in regard to precipitation showed that seasonal and interannual fluctuations of biological oxygen demand (BOD), total nitrogen (TN) and pH were minor, whereas conductivity, suspended solids (SS), and total phosphorus (TP) were largely varied in response to the magnitude of rainfall. The CHL maxima occurred immediately after the spate of TP during the high flow, indicating that phytoplankton growth was directly controlled by phosphorus. Empirical linear models of CHL-TP indicated that the variation of CHL in premonsoon was accounted 60% ($R^2$ = 0.60, p < 0.05, n = 54) by TP. In the mean time, empirical models of annual CHL-TN showed that the variation of CHL was weakly accounted ($R^2$ = 0.16, p < 0.001) by TN and more strongly ($R^2$ = 0.44, p < 0.001) by TP. Thus, the variation of CHL was more explained by the variation of TP than TN. In situ tests of Nutrient Enrichment Bioassays (NEBs) showed that the growth of CHL was greater in the P-treatments (as $PO_4-P$) than the control and N-treatment (as $NO_3-P$). Overall, our results suggest that phosphorus was aprimary limiting nutrient controlling the seasonal phytoplankton growth, based on the in situ experiments of NEBs.

• Journal of Popular Narrative
• /
• v.27 no.2
• /
• pp.13-44
• /
• 2021

This article describes the fear of infection through the Covid19 pandemic and the rapid phase change of human species with H. P. Lovecraft's fiction and "Project LC. RC". Pandemic and climate change, which can be called global weirding, fundamentally question the status and history of human species in the ecosystem. The horror creature and cosmological indifferentism in Lovecraft's weird fiction are contemporary in that they help shed light on today's global weirding. But Lovecraft's racism allows him to ask more fundamental questions about the logjam of his cosmic horror. "Project LC. RC" are a Korean writers's works of cultural variation that rewrites controversial racism and misogyny in Lovecraft's fiction. Such variation becomes the task of creating a mutation in Lovecraft as it becomes infected with the affection of Lovecraft's writing. This article first noted the creative power of Lovecraft's fiction that induces such a mutation. And under this premise, this article wanted to reveal the meaning of Lee Seo young, Eun rim, and Kim Bo young's recreates of Lovecraft's fiction through the analysis of images and motifs of abject, plant creature and symbiosis. Specifically, Lovecraft's creature, which evokes phallic fear, turns into an image of an abject embracing and comforting women's despair("I Want You to Stay Low"), a plant creature that provides women with refuge("Color in the Well"), and a creature of care and symbiotic life("A Sea of Plague"). This recreate/rewriting has contemporary significance in that it embodies values such as labor, care, and solidarity in their works. The conclusion noted another power of creative variation in Lovecraft's fiction, which is not reduced to recreate/rewriting.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.824-827
• /
• 2000

Fabrication of InP-based photonic devices by dry etch Process is important for clear formation of waveguide mesa structure. We have developed more efficient etch process of the inductively coupled plasma (ICP) with low damages and less polymeric deposits for the InP-based photonic devices than the reactive ion etching (RIE) technique. We report the tendency of etch rate variation by the process parameters of the RF power, pressure, gas flow rate, and the gas mixing ratio. The surface roughness of InP-based waveguide structure was more improved by the light wet etching in the mixed solution of H$_2$SO$_4$:H$_2$O (1:1)