• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.36D no.10
• /
• pp.17-22
• /
• 1999

In this paper, the results of the studies about a new proposal where the ONON(oxide-nitride-oxide-nitride) layer instead of the conventional ONO(oxide-nitride-oxide) layer is used as the IPD(inter-poly-dielectrics) layer to improve the data retention problem in the Flash EEPROM cell, have been discussed. For these studies, the stacked-gate Flash EEPROM cell with an about 10nm thick gate oxide and on ONO or ONON IPD layer have been fabricated. The measurement results have shown that the data retention characteristics of the devices with the ONO IPD layer are significantly degraded with an activation energy of 0.78 eV. which is much lower than the minimum value (1.0 eV) required for the Flash EEPROM cell. This is believed to be due to the partial or whole etching of the top oxide of the IPD layer during the cleaning process performed just prior to the dry oxidation process to grow the gate oxide of the peripheral MOSFET devices. Whereas the data retention characteristics of the devices with the ONON IPD layer have been found to be much (more than 50%) improved with an activation energy of 1.10 eV. This must be because the thin nitride layer on the top oxide layer in the ONON IPD layer protected the top oxide layer from being etched during the cleaning process.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.1
• /
• pp.109-114
• /
• 2011

This study was conducted to investigate the effect of hydraulic retention time(HRT) on the power density in a horizontal flow microbial fuel cell(MFC) reactor. When HRTs were 15min, 30min, 60min and 180min, maximum power densities were $24.7mW/m^2$, $27.3mW/m^2$, $22.8mW/m^2$ and $17.2mW/m^2$, respectively. The highest power density was obtained at HRT of 30min. It was 59% improvement when compared to the power density at an HRT of 180min. When HRT was increased, COD removal rate increased whereas the coulombic efficiency remained constant. The result shows that the optimal performance of the horizontal flow MFC reactor could be achieved at HRT of 30min.

• Journal of Nutrition and Health
• /
• v.31 no.1
• /
• pp.5-12
• /
• 1998

This study was designed to examine how dietary protein levels affect organ growth and protein metabolism in early and normally weaned rats. Early and normally weaned rats separated fro the dam on the 15th and 121st day postpartum, respectively. were fed diets containing three levels of protein : low(10%) , normal (20%),and high(40%) . On the 35th day, the weight and DNA, RNA and protein contents in brain , liver, and kidney were determined to ascertain organ and cellular growth. Furthermore, serum total protein , albumin , $\alpha$-amino N and creatine and urinary urea N, and creatinine were determined in order to ascertain protein metabolism and renal functions. Dietary protein levels were not observed to significantly affect total DNA content, which may represent an index of cell number in the liver, brain and kidney. Fresh weight and protein/DNA ratio, which may represent indices of cell size, significantly increased in proportion to dietary protein in the kidney. As for the early weaned rats , the liver cell size significantly decreased. Dietary protein levels and weaning periods did not affect serum total protein and albumin . However, serum urea-N significantly increased in proportion to dietary protein levels whereas serum $\alpha$-amino N was decreased by early weaning . Nitrogen retention was lower in early weaned rats fed low or high levels of protein than in normally weaned rats. The results demonstrate that low or high levels of dietary protein have less desirable effects on protein metabolism in prematurely weaned rats.

• The Journal of Korean Medicine
• /
• v.24 no.2
• /
• pp.159-165
• /
• 2003

Objectives : Coptidis rhizoma (CR) is an oriental medicine that has been used in many traditional prescriptions against diabetes mellitus in Korea for centuries. Our purpose was to determine the protective effect and its action mechanism of CR on the cytotoxicity of pancreatic -cell line (RINm5F cell). Methods : In this experiment, we used methods such as MTT assay for detection of cytotoxicity, DNA fragmentation assay for detection of apoptotic cell death, LDH activity assay for detection of necrotic cell death, and measurement of $DiOC_{6}$ (3) retention for detection of mitochondrial membrane potential (MMP). Background : Nitric oxide (NO) is believed to playa key role in the process of pancreatic -cell destruction leading to insulin-dependent diabetes mellitus (IDDM). Results : Exposure of RINm5F cells to chemical NO donor such as S-nitroso-N-acetylpenicillamine (SNAP) induced cytotoxic events such as DNA fragmentation and lactate dehydrogenase (LDH) release into medium. However, pretreatment of RINm5F cells with CR extract ($10~50{\mu\textrm{g}}/ml$) for 3 hours prevented SNAP-induced DNA fragmentation and LDH release into medium through the inhibition of MMP disruption. Conclusions : These results suggest that CR may be a candidate for a therapeutic or preventing agent against IDDM.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.9
• /
• pp.1434-1443
• /
• 2019

Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.

• 한국전기화학회:학술대회논문집
• /
• 1999.11a
• /
• pp.137-146
• /
• 1999

The rechargeable alkaline manganese dioxide(RAM)battery system has reached a performance level that enables the consumer to utilize RAM for practically all applications where currently single use cells(alkaline manganese, zinc-carbon)are being used. In addition, it can replace nickel-cadmium and nickel-metal hydride cells in low to medium power applications with much improved charge retention at higher operating temperatures and in intermittent use and works well with solar charging. A review is given on RAM cell performance as well as a comparison to competing rechargeable technologies. Potential new possibilities in the field of OEM(original equipment manufacturer) applications are discussed.

• Fashion & Textile Research Journal
• /
• v.9 no.5
• /
• pp.569-572
• /
• 2007

The effectiveness of Palmarosa, Neroli and Jasmin blending oil on dry skin of rat induced by kitchen detergent are investigated. The experimental groups were divided the control group, group treated with surfactant, group treated with Palmarosa and Neroli, and group with Palmarosa, Neroli and Jasmin. Observation of epidermis and the alteration of mast cell were performed with photomicroscope. According to the epidermis morphological changes analysis, the A3 group treated with Palmarosa, Neroli and Jasmin blending oil was appeared the most similar with the control group, and the A2 group applied with Palmarosa and Neroli blending oil was sequently displayed similar characteristics. The collagen layer's breakaway resulting from Palmarosa essential oil, the collagen layer's restoration resulting from Neroli essential oil, the collagen layer's retention hyperkeratosis resulting from Jasmin essential oil were observed in the structure of the epidermal layer. In photomicrosope observation of mast cell to examine the inflammatory reactions, the increase in size and number of mast cell were showed in A1 group treated with surfactant compared to the control group. The number of mast cells definitely decreased in groups which were treated with Palmarosa, Neroli and Jasmin blending oil.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.119-120
• /
• 2007

반도체 공정에서 사용되는 ILD막질 중 oxy-nitrde(SiON) film은 contact etch stopper, photo공정을 위한 ARL(anti-reflection lay떠 그리고, 후속공정의 plasma damage에 대한 blocking layer로서의 역할을 담당하며 많은 공정에 널리 사용되고 있다. 그러나 막질 자체의 불완전성 (trap site, dangling bond)에 의해 cell current instability(CCI) 특성을 악화 시킬 수 있어 이에 대한 원인규명 및 대책이 요구되었다. 본 연구는 미국 S사(社) super flash memory에서 oxy-nitride 막질 증착 시의 gas flow량에 따른 CCI 특성변화를 연구하고 최적의 공정조건을 제시하고자 한다.

• Archives of Pharmacal Research
• /
• v.3 no.1
• /
• pp.7-12
• /
• 1980

Ampliciline was synthesized from 6-amino-pencillanic acid (6-APA) and D-.alpha. phenylglycine methyl ester by using amplicilin synthesizing enzyme from Peudomonas melanogenum (IAM 1655). The whole cell enzyme was immobilized by entrapping it in the polyacrylamide gel lattices. The polymer used in the enzyme entrapment was made from 150 mg per ml of acrylamide monomer and 8 mg per ml of N, N'-methylenebisacrylamide. About 200 mg/whole cell enzyme was mixed in the polymer for entrapment. The maximal activity retention after immobilization was 56%. The optimal pH values for the whole cell enzyme and the immobilized whole cell enzyme were 6.0 and 5.9, respectively. The optimal temperature for the enzyme activity were the same for both type of preparations. The enzyme stabilities against pH and heat increased for immobilized whole cell enzyme. Immobilized cell was more stable especially in the acidic condition while both type were found to be very suceptible to thermal inactivation at a temperature above 4.deg.C. The kinetic constants obtained from Lineweaver-Burk plot based on two substate reaction mechanism showed somewhat higher value for immobilized whole cell enzyme as compared to the whole cell enzyme : the Km value for 6-APA were 7.0 mM and 12.5 mM while Km values for phenylglycine methyl ester were 4.5 mM and 8.2 mM, respectively. Using the immobilized whole cell enzyme packed in a column reactor, the productivity of ampiciline was studied by varying the flow rate of substrate solution. At the space velocity, SV, 0.14 hr$^{-1}$ the conversion was 45%. Operational stability found in terms of half life was 30 hr at SV = 0.2 hr.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.99-100
• /
• 2009

SGOI 1T-DRAM cells with various Ge mole fractions were fabricated and compared to the SOI 1T-DRAM cell. SGOI 1T-DRAM cells have a higher leakage current than SOI 1T-DRAM cell at subthreshold region. The leakage current due to crystalline defects and interface states at Si/SiGe increased with Ge mole. This phenomenon causes sensing margin and the retention time of SGOI 1T-DRAMs decreased with increase of Ge mole fraction.