• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.848-854
• /
• 1998

To concentrate polyunsaturated fatty acids from anchovy oil by supercritical carbon dioxide $(SC-CO_2)$, effects of different adsorbents, cosolvents and extraction pressures on the extraction yield and fatty acid composition in the extract and the residue fractions were investigated. Anchovy oil mixed with silver nitrate-coated silica gel showed higher extraction yield and concentration of EPA and DHA in the residual fraction than that mixed with only silica gel at $60^{\circ}C/345{\;}bar$. Ethyl acetate was a promising cosolvent for concentrating polyunsaturated fatty acids in the residual fraction from anchovy oil mixed with silica gel. For the extraction pressures tested, 276 bar showed a maximum value in the extraction yield and concentration of EPA and DHA in the residue. Starting with anchovy oil containing 13.3% EPA and 16.2% DHA mixed with a silver nitrate-coated silica gel, the residue fraction containing 28.2% EPA and 38.3% DHA was obtained when ethyl acetate was used as a cosolvent with $SC-CO_2$ at $60^{\circ}C/276{\;}bar$.

• Current Photovoltaic Research
• /
• v.2 no.2
• /
• pp.63-68
• /
• 2014

In recent years, discoloration defects, called as snail trail, have been observed at many crystalline photovoltaic modules after a period of time ranging from several months to several years after initial installation. It has been reported that this phenomenon doesn't impact on the performance of photovoltaic modules, but it can be detected through simple visual inspection. The origin and detailed mechanism for the formation have not been identified. In this study, non-destructive analysis by Raman spectroscopy has been carried out to investigate the origin of this phenomenon. In parallel, destructive analysis by scanning electron microscopt and transmission electron microscopy was also performed in order to confirm the results from non-destructive method. Through the extensive analysis, it was found that the main cause for discoloration is the formations of $Ag_2CO_3$ and $AgC_2H_3O_2$. Detailed mechanism for the formation of these particles was indentified through systematic studies.

• Journal of the Korean Chemical Society
• /
• v.13 no.2
• /
• pp.141-147
• /
• 1969

Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10b
• /
• pp.63-66
• /
• 2003

최근 미래를 선도해 갈 것으로 인정받는 최첨단 기술로서 나노기술(NT), 바이오기술(BT), 정보기술(IT)이 있다. 나노기술은 원자나 분자 정도로 미세한 크기의 물질을 다루는 기술로 형태학적인 특성에 기인한 물리적 및 화학적인 장점을 활용한 연구가 활발히 이루어지고 있다. 나노섬유는 현재 섬유 관련 분야에서 가장 많은 연구가 이루어지고 있는 주제로 섬유의 직경이 수십 nm ~ 수 $\mu\textrm{m}$ 수준인 섬유를 말한다. (중략)

• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.120.2-120.2
• /
• 2007

See Full Text

• Journal of Korean Physical Therapy Science
• /
• v.10 no.2
• /
• pp.199-207
• /
• 2003

The present study examined that in vivo/vitro test is investigated in normotensive sham-operated rats(NSR) and aldosterone-analogue deoxycorticosterone acetate (DOCA)-salt hypertensive rats(ADHR) and that the antiliypertensive effect was induced by silver spike point(SSP) electrical stimulation at meridian points(CV-3, -4, Ki-12, SP-6, LR-3, BL-25, -28, -32, -52), specifically, such as aldosterone in 24 hour urine analysis from normal volunteer. The heart weight, the tickness of vascular wall, collagen fiber and the systolic blood pressure were significantly increased in ADHR than that in NSR. The required time of PSS-induced resting tone and the phosphorylation of stress-activated protein kinase/c-Jun N-terminal protein kinase(SAPK/JNK) were significantly increased in ADHR than that in NSR. However, the Kv currents were significantly decreased in ADHR than that in NSR. The current of 1 Hz continue type of SSP electrical stimulation significantly decreased in excretion of urine aldosterone from normal volunteer. These results suggest that the development of aldosterone analogue-induced hypertension is associated with changed heart weight, content of collagen fiber, tickness of vascular wall, blood pressure, resting tone, voltage-dependent K+ current(Kv) and phosphorylation of SAPK/JNK, which directly affects blood pressure. Therefore the hypertension is a risk factor on cerebrovascular disease. Moreover, These results suggest that the SSP electrical stimulation, especially current of 1 Hz continue type, significantly regulates excretion of urine aldosterone from volunteer.

• Journal of Korean Physical Therapy Science
• /
• v.10 no.1
• /
• pp.158-169
• /
• 2003

The present study examined that in vivo test is investigated in sham-operated(control group) and aldosterone-analogue deoxycorticosterone acetate (DOCA)-salt hypertensive animals(experimental group) and that the antihypertensive effect was induced by silver spike point(SSP) low frequency electrical stimulation at meridian points(CV-3, -4, Ki-12, SP-6, LR-3, BL-25, -28, -32, -52), specifically, such as diuretic action in 24 hour urine analysis from normal volunteer. The $Na^+$ and $Ca^{2+}$ ions were significantly increased in aldosterone-analogue DOCA-salt hypertensive rats than that in sham-operated rats. However, the $K^+$ ions were significantly decreased in aldosterone-analogue DOCA-salt hypertensive rats than that in sham-operated rats. The current of 1 Hz continue type of SSP low frequency electrical stimulation significantly increased in excretion of urine $Na^+$ and $K^+$ ions from normal volunteer. However, the excretion of $Ca^{2+}$ ion were significantly decreased by SSP electrical stimulation in volunteer. These results suggest that the development of aldosterone analogue-DOCA-salt hypertension is associated with changed $Na^+$, $K^+$ and $Ca^{2+}$ ions of urine. which directly affects blood pressure. Therefore, the hypertension is a risk factor on cardiovascular disease. Moreover, These results demonstrate that the SSP low frequency electrical stimulation, especially current of 1 Hz continue type, significantly regulates $Na^+$, $Ca^{2+}$ and $K^+$ ions from volunteer. Therefore, the SSP low frequency electrical stimulation is a good regulator through a diuretic action of aldosterone-induced hypertension.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.05a
• /
• pp.235-236
• /
• 2009

금속 아세테이프가 금속으로 열분해하는 반응을 이용하여 템플레이트 안에 잘 정렬된 금속 나노 구조물을 얻는 것은 센서 (sensor), 분리 막(separation), 저장 장치(storage), 에너지 전환 장치 (energy conversion)에 응용이 가능하다. 실버 아세테이트와 팔라듐 아세테이트에서 순수 실버와 팔라듐 나노 구조의 제조 및 형태의 차이를 밝히는 것을 목적으로 나노 입자의 크기와 활성화 에너지가 이에 영향을 주는 것으로 확인할 수 있었다. 금속 나노 구조의 확인 및 나노입자의 크기와 활성화 에너지를 분석 관찰하기 위해 DSC, TG, XRD, FE-SEM 등을 이용하였다.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2007.10a
• /
• pp.121.1-121.1
• /
• 2007

See Full Text

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.3
• /
• pp.224-228
• /
• 1990

Cabbage contained high peroxidase activity among tested plant sources. The cabbage peroxi-dase can replace horseradish peroxidase to assay glucose with glucose oxidase. The amount of glucose can be determined quantitatively by glucose oxidase-cabbage peroxidase. The opti-mum pH and temperature for enzymatic glucose determination by glucose oxidase-cabbage peroxidase were 6.0 and 35-45$^{\circ}C$ respectively. The glucose assay was inhibited by addition of various metal salts such as mercuric chloride lead acetate silver nitrate ammonium molyb-date sodium tunstate and cupric sulfate. The relationship between absorbance and amount of glucose was linear up to 8.33 mM glucose in the assay mixture under the assay conditions.