• Korean journal of food and cookery science
• /
• v.14 no.4
• /
• pp.394-399
• /
• 1998

The juice of garlic (Euichun variety) was extracted and concentrated by heating at 90$^{\circ}C$, by using a rotary vacuum evaporator at 45$^{\circ}C$, or by freezing at -50$^{\circ}C$ until the volume was reduced to 70% of the original's. The concentrated garlic juice was packed into 15 ml test tubes wrapped with aluminum foil and kept at 4$^{\circ}C$ or 25$^{\circ}C$ for 60 days. Changes of browning, microbiological and sensory characteristics of the concentrated garlic juices were monitored every 10 days. The specific gravity and viscosity of the prepared juices decreased in the juices concentrated at 90$^{\circ}C$, 45$^{\circ}C$ and -50$^{\circ}C$ in order. Browning of the concentrated garlic juices was slower during the storage at 4$^{\circ}C$ than at 25$^{\circ}C$. Browning occurred rapidly in the juice concentrated at 45$^{\circ}C$ during the storage, especially at 25$^{\circ}C$. The numbers of mesophilic and psychrotrophic bacteria in the juices did not increase significantly during the storage, which means the garlic juices had good shelf-life. The CFUs/ml of garlic juice concentrated at 90$^{\circ}C$ were lower about 1 to 2 log cycles than those in other concentrated juices. The juice concentrated at 90$^{\circ}C$ showed the weakest garlic odor and the strongest cooked odor among the juices. The juice concentrated at -50$^{\circ}C$ had the freshest odor, especially stored at 4$^{\circ}C$, but the juice concentrated at 90$^{\circ}C$ had lowest score in fresh odor. Brown color was dark in the juice concentrated at 45$^{\circ}C$ and green color of all the juices did not change significantly during the storage.

• Korean Journal of Microbiology
• /
• v.54 no.1
• /
• pp.60-68
• /
• 2018

A cold-active and alkaline serine protease (Pro21717) was partially purified from the Antarctic marine bacterium Pseudoalteromonas arctica PAMC 21717. On a zymogram gel containing skim milk, Pro21717 produced two distinct clear-zones of approximately 37 kDa (low intensity) and 74 kDa (high intensity). These were found to have identical N-terminal sequences, suggesting they arose from an identical precursor and that the 37 kDa protease might homodimerize to the more active 74 kDa form of the protein. Pro21717 displayed proteolytic activity at $0-40^{\circ}C$ (optimal temperature of $40^{\circ}C$) and maintained this activity at pH 5.0-10.0 (optimal pH of 9.0). Notably, relative activities of 30% and 45% were observed at $0^{\circ}C$ and $10^{\circ}C$, respectively, in comparison to the 100% activity observed at $40^{\circ}C$, and this enzyme showed a broad substrate range against synthetic peptides with a preference for proline in the cleavage reaction. Pro21717 activity was enhanced by $Cu^{2+}$ and remained stable in the presence of detergent surfactants (linear alkylbenzene sulfonate and sodium dodecyl sulfate) and other chemical components ($Na_2SO_4$ and metal ions, such as $Ba^{2+}$, $Mg^{2+}$, $Ca^{2+}$, $Zn^{2+}$, $Fe^{2+}$, $K^+$, and $Na^{2+}$), which are often included in commercial detergent formulations. These data indicate that the psychrophilic Pro21717 has properties comparable to the well-characterized mesophilic subtilisin Carlsberg, which is commercially produced by Novozymes as the trademark Alcalase. Thus it has the potential to be used as a new additive enzyme in laundry detergents that must work well in cold tap water below $15^{\circ}C$.

• Journal of Korea Society of Industrial Information Systems
• /
• v.24 no.5
• /
• pp.9-16
• /
• 2019

In today's global energy market, the importance of green energy is emerging. Hydrogen energy is the future clean energy source and one of the pollution-free energy sources. In particular, the fuel cell method using hydrogen enhances the flexibility of renewable energy and enables energy storage and conversion for a long time. Therefore, it is considered to be a solution that can solve environmental problems caused by the use of fossil resources and energy problems caused by exhaustion of resources simultaneously. The purpose of this study is to efficiently produce hydrogen using plasma, and to study the optimization of DME reforming by checking the reforming reaction and yield according to temperature. The research method uses a 2.45 GHz electromagnetic plasma torch to produce hydrogen by reforming DME(Di Methyl Ether), a clean fuel. Gasification analysis was performed under low temperature conditions ($T3=1100^{\circ}C$), low temperature peroxygen conditions ($T3=1100^{\circ}C$), and high temperature conditions ($T3=1376^{\circ}C$). The low temperature gasification analysis showed that methane is generated due to unstable reforming reaction near $1100^{\circ}C$. The low temperature peroxygen gasification analysis showed less hydrogen but more carbon dioxide than the low temperature gasification analysis. Gasification analysis at high temperature indicated that methane was generated from about $1150^{\circ}C$, but it was not generated above $1200^{\circ}C$. In conclusion, the higher the temperature during the reforming reaction, the higher the proportion of hydrogen, but the higher the proportion of CO. However, it was confirmed that the problem of heat loss and reforming occurred due to the structural problem of the gasifier. In future developments, there is a need to reduce incomplete combustion by improving gasifiers to obtain high yields of hydrogen and to reduce the generation of gases such as carbon monoxide and methane. The optimization plan to produce hydrogen by steam plasma reforming of DME proposed in this study is expected to make a meaningful contribution to producing eco-friendly and renewable energy in the future.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.5
• /
• pp.48-53
• /
• 1998

Poly-Si TFT's could be fabricated on glass substrates by metal induced lateral crystallization (MILC) method at 450.deg. C. Channel area of the poly-Si TFT's was laterally crystallized from source and drain areas, where a thn nickel film was deposited. Dopants activation for the formation of source and drain region could be achieved by thermal annealing at 450.deg. C after the ion mass doping of phosphorus. The field effect mobility of thus formed N-channel poly-Si TFT's was 76cm$^{2}$/Vs, and the on/off current ratio was higher than 7E6.

• Korean journal of applied entomology
• /
• v.48 no.3
• /
• pp.361-368
• /
• 2009

We have investigated some biological characteristics, such as survival rate and fecundity, of Orius laevigatus and Phytoseiulus persimilis, which have been stored at 6, 8, 10, $12{\pm}1^{\circ}C$, RH $70{\pm}10%$, in dark condition. Overall, an appropriate temperature for cold storage was $10^{\circ}C$ for O. laevigatus and $8^{\circ}C$ for P. persimilis. 70% of adult O. laevigatus could survive for 36 days at $10^{\circ}C$. The O. laevigatus stored at $10^{\circ}C$ for $10{\sim}50$ days laid $37.1{\sim}120.5$ eggs. Since fresh (no storage) O. laevigatus laid 224.5 eggs, comparative fecundity of stored adults was $16.5{\sim}53.7%$ of normal fecundity. P. persimilis stored at $8^{\circ}C$ for $7{\sim}2$ days with (food eggs of Tetranychus urticae) laid $11.9{\sim}18.9$ eggs. Since fresh P. persimilis laid 26.4 eggs, comparative fecundity of stored adults was $45.1{\sim}71.6%$ of normal fecundity.

• Economic and Environmental Geology
• /
• v.45 no.2
• /
• pp.157-167
• /
• 2012

This study aimed to interpret the provenance and firing temperature of pottery from Chipyeongdong site in Gwangju, Korea though mineralogical and geochemical methods and also investigated the post-depositional alteration of pottery in burial environments. It is also presumed that they were made of soils near the site because they have similar mineralogical composition and same geochemical evolution path. Based on the results of mineralogical analysis, the pottery samples are largely divided into 2 groups; $700^{\circ}C$ to $1,000^{\circ}C$ and 1,000 to $1,100^{\circ}C$. At some pottery fired at over $1,000^{\circ}C$, it is thought that the refinement of raw materials were processed to remove macrocrystalline fragments. However, it was found that phosphate in soil environments formed amorphous aggregates with Al and Fe within the pores and voids on pottery fired at the low temperature. It indicates the contamination of pottery after burial.

• Journal of Bio-Environment Control
• /
• v.22 no.3
• /
• pp.262-269
• /
• 2013

This study was carried out in order to examine the germination characteristics of Ligularia fischeri seeds, and it was to develop the more efficient pre-treatment and production system of the seeds. It was performed by two ways - temperature control (10, 15, 20 and $25^{\circ}C$) and shading treatment (Full sunlight, 35%, 50%, 75% and 95% of full sunlight). Seed pre-treatment before the each experiment was carried out by temperature (with low temperature and wetting treatment (LTW) for 0, 15, 30, 45 and 60days) and shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 2 days). Seeds of L. fischeri were, regardless of seed pre-treatment, germinated well at $10^{\circ}C$ and the more temperature went up, the more germination rate went down. As a result of surveying shading treatment, 75% shading with DRT was the highest germination rate (68.1%) and 95% shading with WS was the lowest germination rate (48.6%). It was showed over-growth under 95% shading treatment experiment and withered in the full sunlight. As a result of surveying the whole experiment, L. fischeri seeds pre-treated with LTW for 15 days germinated well at $10^{\circ}C$ and under 50~75% shading treatment.

• Korean Journal Plant Pathology
• /
• v.13 no.3
• /
• pp.152-159
• /
• 1997

Six pathogenic Pythium isolates obtained from diseased ginger rhizomes were identified as Pythum myriotyrum Drechsler based on various morphological and physiological characteristics. The isolates showed strong virulence on underground parts of buds, crowns, rhizomes, roots and aerial parts of leaves and stems as well. The isolates caused rot of germinated seeds of 10 different crops tested, including cucumber and pepper, and markedly inhibited seedling growth of 3 crops tested, including corn and barley. Maximum, optimum and minimum growth temperatures for P. myriotylum were 39~45$^{\circ}C$, 33~37$^{\circ}C$ and 5~7$^{\circ}C$, respectively. Optimum pH for the growth was 6~7. Mycelial linear growth was most rapid on V-8 juice agar, but aerial mycelia were most abundant on PDA and corn meal agar. Zoosporangial and oogonial formation was greatest on V-8 juice agar. Optimum temperatures for the production of zoosporangia and oogonia were 20~35$^{\circ}C$ and 15$^{\circ}C$, respectively.

• Korean Journal of Plant Tissue Culture
• /
• v.22 no.4
• /
• pp.229-234
• /
• 1995

Anthers of hybrids and inbred lines of Chinese cabbage (Brassica campestris ssp. pekinensis) were inoculated on the modified solid or liquid B$_{5}$ medium after several pre-treatments. Anthers were then maintained at 25 $^{\circ}C$ after being subjected to various post-treatment. Somatic embryos began to appear 9 days after inoculation and ended at 13th days. Low temperature pre-treatment did not increase embryoid production whereas high post-treatment temperature of 4$0^{\circ}C$ or 45$^{\circ}C$ enhance the production. There were considerable levels differences in embryogenesis between lines used, but not between the culture methods. Somatic embryo yield was also increased by subjecting anthers to one day at 35$^{\circ}C$ and then another one day at 3$0^{\circ}C$ after plating. Histological observations showed several stages in haploid development ranging from a few celled to large multiple-celled embryoids.s.

• Korean Journal of Plant Resources
• /
• v.31 no.4
• /
• pp.363-371
• /
• 2018

Tiarella polyphylla D. Don is a native plant distributed only in Ulleung Island in Korea and has been traditionally used for medicinal purposes, although it is also used ornamentally. This study was conducted to determine the requirements for dormancy break and germination and to classify the type of seed dormancy. The experiments were performed with cold stratification (0 or 12 weeks at $5^{\circ}C$), warm stratification (0, 4, 8, or 12 weeks at $23^{\circ}C$, followed by 8 weeks at $5^{\circ}C$, and then incubation at $23^{\circ}C$), and $GA_3$ treatments (0, 10, 100, or 1000 mg/L). The treated seeds were incubated on aseptic media at room chamber ($23^{\circ}C$, a 16h photoperiod of fluorescent lamps with $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The seeds were dispersed in nature as underdeveloped embryos with no physical barrier to absorb water to prevent water absorption. However, the seeds did not germinate for 30 days after sowing without any pre-treatments. Thus, the seeds had morphological dormancy (MD) and physiological dormancy (PD). The final germination percentage following cold stratification (0 or 12 weeks) was 66.7% and 45.6%, respectively. The cold stratification delayed seed germination by about 3 weeks. In the warm stratification experiment (0, 4, 8, or 12 weeks), the final germination percentage was 21.1%, 27.8%, 41.1%, and 57.8%, respectively, 20 weeks after sowing. The embryos of the T. polyphylla seed grew in relatively warm temperatures ($23^{\circ}C$). $GA_3$ application overcame seed dormancy and promoted germination. Following $GA_3$ treatment (0, 10, 100, or 1000 mg/L), the final germination percentage was 33.3%, 45.0%, 42.5%, and 72.5%, respectively. These results suggest that the T. polyphylla seeds had non-deep simple morphophysiological dormancy (MPD) and $GA_3$ treatment could be used as a substitute for warm stratification for breaking seed dormancy. To our knowledge, this is the first report of seed dormancy characteristics of the genus Tiarella native to Korea.