• Journal of Electrochemical Science and Technology
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• 제10권4호
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• pp.387-393
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• 2019

Activated carbons (ACs) are considered important electrode materials for supercapacitors because their large specific surface areas lead to high charging capacities. In the conventional synthesis of ACs, a substantial amount of carbon is lost during carbonization of a precursor. The development of a method to synthesize ACs in high yield would lower their manufacturing cost. Here, we demonstrate the synthesis of high-specific-surface-area NaOH-AC from carbon prepared via a hydrothermal carbonization (HTC) route, with a higher yield than that achieved through conventional pyrolysis carbonization. The amorphous carbon was derived from HTC of sugar and subsequently activated at 800℃ with various NaOH etchant/C ratios under a N₂ atmosphere. The AC prepared at 4:1 NaOH/C exhibited the highest surface area (as high as 2,918 ㎡ g^-1) and the highest specific capacitance (157 F g^-1 in 1 M aqueous Na₂SO₄ electrolyte solution) among the NaOH-AC samples prepared in this work. On the basis of their high specific capacitance, the NaOH-ACs prepared from HTC sugar are suitable for use as electrode materials for supercapacitors.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2000년도 국제심포지움
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• pp.5-6
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• 2000

Nitric oxide (NO) is a simple combined molecule of oxygen and nitrogen, and has a wide variety of action on the physiological and pathophysiological function of the body. It is a key transducer of the vasodilator message from the endothelium to vascular cells. However, its different roles have been elucidated by numerous researches, which was undertaken in the 80's and 90's. Three types of NO synthase were involved in synthesizing NO and they are identified in different tissues and cells including macrophage, endothelial cells and even tumor cells. In the late 90's, we undertook a number of researches for elucidating the effect of NO on embryo development, since developmentally arrested bovine embryos contained large amount of NO metabolites in their cytoplasm. Subsequently, we found that the addition of a spontaneous NO donor to culture medium markedly inhibited embryo development and that its inhibitory role was independent of embryonic genome activation. Research was focused to find a way to prevent the inhibitory action of NO on embryo development and demonstrated that the addition of hemoglobin, a NO scavenger, to embryo culture medium greatly stimulated in vitro-development of bovine and mouse embryos. Based on these research outcomes, we developed a NO action-free culture system for embryos and other tissues. The efficacy of such system has subsequently been confirmed by achieving the high rates of preimplantation development and blastocyst formation in the NO action-free culture of mouse and bovine embryo. In this article, we briefly introduced the nature of NO and our research outcomes on the role of NO in embryo development.

• 한국축산식품학회지
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• 제34권1호
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• pp.65-72
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• 2014

This study is executed to develop probiotics which produce S-adenosyl-L-methionine (SAM), a methyl group donor of the 5-methyltetrahydrofolate methylation reaction within the animal cell. SAM is an essential substance for the synthesis, activation, and metabolism of hormones, neurotransmitters, nucleic acids, phospholipids, and cell membranes of animals. The SAM is also known as a nutritional supplement to improve brain functions of the human. In this study, the SAM-producing strains are identified in 18 types of salted fish, and then, the strains with excellent SAM productions are being identified, with 1 strain in the Enterococcus genus and 9 strains in the Bacillus genus. Strains with a large amount of SAM production include the lactic acid bacteria such as En. faecium and En. durans, En. sanguinicola, as well as various strains in the Bacillus genus. The SAM-overproducing strains show antibacterial activities with certain harmful microbes in addition to the weak acid resistances and strong bile resistances, indicating characteristics of probiotics. It is possible that the jeotgal-originated beneficial strains with overproducing SAM can be commercially utilized in order to manufacture SAM enriched foods.

• 대한본초학회지
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• 제25권3호
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• pp.73-80
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• 2010

Objectives：The present study purposed to evaluate the effects of Leonuri Herba and Leonuri Semen on hypercholesterolemia and provide data for the appropriate clinical application of Leonuri Herba and Leonuri Semen. Methods：We applied the water extracts of Leonuri Herba and Leonuri Semen to rats with hypercholesterolemia induced by high-cholesteroldiet, and examined their effects. Results：The levels of the total cholesterol and LDL-cholesterol were reduced by the uptake of Leonuri Herba to rats with hypercholesterolemia, but there was no significant effect on the level of TG(triglyceride), HDLc(HDL-cholesterol), FFA(free fatty acid), and Fc(free cholesterol), while the amount of AST and ALT was inhibited. The application of Leonuri Semen brought about the decrease of the total cholesterol and Fc, the increase of TG, HDLc, and FFA, and the significant decrease of the activation of AST. Leonuri Herba had only a weak effect on hypercholesterolemia, while Leonuri Semen had a strong effect on the reduction of the symptoms of hypercholesterolemia. Conclusion：Based on the fact that Leonuri Herba had only a weak effect on hypercholesterolemia, while Leonuri Semen had a strong effect on the reduction of the symptoms of hypercholesterolemia, it is concluded that Leonuri Semen is a better solution for hypercholesterolemia than Leonuri Herba.

• 한국연소학회지
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• 제14권3호
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• pp.16-23
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• 2009

It is strongly desired for coal-fired power plants to utilize not only low-rank coals with high moisture contents, but also lowering cost with diversifying fuel sources. In this study, combustion characteristics of low rank coal with high moisture, and standard pulverized coals are experimentally investigated using TGA (Thermogravimetric Analysis) and DTF (drop tube furnace). The coals tested are three kinds of coal with moisture content ranging from 8.32 to 26.82%. The results show that under the air combustion condition, the burn-out time at TGA rises as moisture content increases, and standard pulverized coal with 8.32% moisture content showed the lowest activation energy of 55.73 kJ/mol. In case of the high amount of moisture, the combustion efficiency decreases due to evaporation heat loss, and unburned carbon in ash produced at combustion process in DTF increased. Aslo, initial deformation temperature of slag attached in alumina tube of DTF decreased with lowering the crytallinity of anorthite and augite. To improve the combustion reactivity and efficiency, it is effective to upgrade through drying the high moisture coal to moisture level (less than 10%) of standard pulverized coal.

• 대한세포병리학회지
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• 제7권1호
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• pp.23-30
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• 1996

Chromatin texture, which partly reflects nuclear organization, is evolving as an important parameter indicating cell activation or transformation. In this study, chromatin pattern was evaluated by image analysis of the electron micrographs of follicular and papillary carcinoma cells of the thyroid gland and tested for discrimination of the two neoplasms. Digital grey images were converted from the electron micrographs, nuclear images, excluding nucleolus and intranuclear cytoplasmic inclusions, were obtained by segmentation; grey levels were standardized; and grey level histograms were generated. The histograms in follicular carcinoma showed Gaussian or near-Gaussian distribution and had a single peak, whereas those in papillary carcinoma had two peaks(bimodal), one at the black zone and the other at the white zone. In papillary carcinoma, the peak in the black zone represented an increased amount of heterochromatin particles and that at the white zone represented decreased electron density of euchromatin or nuclear matrix. These results indicate that the nuclei of follicular and papillary carcinoma cells differ in their chromatin pattern and the difference may be due to decondensed chromatin and/or matrix substances.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.455-461
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• 2009

There is a significant amount of experimental evidence suggesting that polysaccharides from mushrooms enhance the host immune system by activating various mechanisms in immune cells, including macrophages. In this study, polysaccharides from Lentinus edodes were found to stimulate the functional activation of macrophages to secrete inflammatory mediators and cytokines and increase the phagocytotic uptake. The chemical properties of the stimulatory polysaccharides, CPFN-G-I, CPBN-G, and CPBA-G, were determined based on their monosaccharide composition, which mainly consisted of glucose and mannose. According to FT-IR and GC/MS, the structure of CPFN-G-I, purified from the fruiting body of L. edodes, was found to consist of a $\beta$-1,6-branched-$\beta$-1,4-glucan, whereas CPBN-G and CPBA-G, purified from the liquid culture broth, were found to be composed of a heteromannan. The configuration of the p-linkage and triple helical conformation of each polysaccharide were confirmed using a Fungi-Fluor kit and Congo red, respectively.

• 한국분말재료학회지
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• 제16권4호
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• pp.262-267
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• 2009

Disk type porous nickel membrane was fabricated by in-situ reduction/sintering process using compacted NiO/PMMA (PMMA; Polymethyl methacrylate) mixture at $800^{\circ}C$ in hydrogen atmosphere. The porosity (49$\sim$58%) of these membrane was investigated as an amount of PMMA additive. The thermal decomposition and reduction behavior of NiO/PMMA were analyzed by TG/DTA in hydrogen atmosphere and the activation energy for the hydrogen reduction of NiO and thermal degradation of PMMA was calculated as 61.1 kJ/mol, evaluated by Kissinger method. Finally, the filtering performance and pressure drop were measured by particle counting system.

• 한국식생활문화학회지
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• 제19권6호
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• pp.678-690
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• 2004

This study was implemented to offer materials for the activation of On-line food shopping mall though census about purchasing food. A percentage of people who had accessed to On-line food shopping mall was 53.8%, and who had an experience of purchasing food at the On-line sopping mali was 18.9%. The number of food purchasing in On-line food market is $1{\sim}3$ times(67.7%). It is general that an amount of food purchase is less than 100,000 wons. And the health assistant food is the most interesting item followed by Meet, Special products like a laver and mushroom, and an anchovy. in purchasing food at On-line market, customer thought that the confidence and the freshness of food are important because customer can't choose a product directly. In the future of food purchase using On-line shopping mall, 38.1% of people show their intend of purchasing at the mall. People who had experience of food purchase though the Internet have more positive view about repurchase than ones had not.

• 한국응용과학기술학회지
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• 제26권4호
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• pp.483-490
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• 2009

This research was conducted to estimate the characteristics of carbon dioxide decomposition using an inorganic sludge. The inorganic sludge was composed of high amount (66.8%) of $Fe_2O_3$. Hydrogen could be reduced with 0.247, 0.433, 0.644, and 0.749 at 350, 400, 450, and $500^{\circ}C$, respectively. The carbon dioxide decomposition rates at 250, 300, 350, 400, 450, and $500^{\circ}C$ were 32, 52, 35, 62, 75, and 84%, respectively. High temperature led to high reduction of hydrogen and better decomposition of carbon dioxide. The specific surface area of the sludge after hydrogen reduction was higher than that after carbon dioxide decomposition. The specific surface area of the sludge was more decreased with increasing of temperature.