• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.232-257
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• 2003

It has been shown that transparent microemulsion gels of flexibly adjustable viscosity containing less than 10％ w/w surfactants can be obtained just by cooling down through a new 1-step preparation procedure (via 4 different in-situ colloidal systems) using PIT-technology with a range of emulsifiers, co-emulsifiers and lipids. They can be used for a wide scope of applications. Specific examples have been given with antiperspirant formulas that proof the stability of these thickened microemulsions even with high content of electrolytes and low pH. We propose that the structure of these microemulsion gels can be described by cross-linking of nano-fine oil droplets via an ABA-triblock copolymer. A new generation of transparent antiperspirant roll-ons with significantly improved skin tolerance can now be formulated as an attractive alternative to alcohol-based products.

• 천문학회보
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• 제39권2호
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• pp.77.2-77.2
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• 2014

Questions of how our Milky Way evolves through the interaction with its environment have been constantly raised. One particularly interesting question is how the metallicity would change as our Milky Way goes through collision with HVCs. Because of the possibility of HVCs providing fuel for star formation in the Galactic disk, we simulate the collision between HVCs and the Galactic disk. More specifically, we trace how the Galactic metallicity changes throughout the process of HVCs colliding with our Milky Way based upon a specific scenario that HVCs are primordial gas left-overs from an ancient galaxy formation. Such mixing between metal-rich gas (disk) and metal-poor HVC can be traced by running numerical simulations with the FLASH code due to its capability of tracking down the abundance change of a specific element such as carbon at each time step of the hydrodynamic evolution. As for now, we give how this mixing depends on model parameters that we choose such as collision speed, initial metallicities, temperature and so on.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.988-989
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• 2015

본 논문은 저압 직류배전의 시스템에 적용하기 위한 ZVS 방식의 100kW 고강압 DC-DC 컨버터를 제안하고 실험을 통하여 타당성을 검증하였다. 제안된 시스템은 저압 직류배전 설비에 구성되는 시스템으로 1500Vdc가 송전될 때 가정이나 공업용으로 사용 가능한 380Vdc로 강압시켜주는 장치이다. 고압 특성상 하드 스위칭시 손실이 커 ZVS 동작이 가능하도록 구성하였고, 구성된 시스템에 대해 정격 실험 결과 100kW 부하에서 95.8%의 효율을 보였다.

• 대한가정학회지
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• 제20권2호
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• pp.119-125
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• 1982

Based on the selected controlled receipe, drying and frying processes were varied inculding time and temperature. According to the panel test and measurement with a texturometer on the products of different drying and frying conditions, the highly acceptable best product was the one prepared as follows. It was placed in the oven at $45^{\circ}C$ for 5 minutes and then at $23^{\circ}C$for 15 minutes. After turning upside down, this drying step was repeatedly continued for 5 hours. It was also dipped into oil at $14^{\circ}C$ for 1 minute, soaked in oil at $120^{\circ}C$for 2 minutes and then fried in oil at $190^{\circ}C$for 2 minutes. The studies using a texturometer showed the products with high acceptability in the panel test had brittleness of 1.3-2cm and number of peaks 4-6. The optimum drying times is considered as 3 hours since there was no significant difference among the products of 3 to 5 hours drying time.

• 한국정보전자통신기술학회논문지
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• 제4권4호
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• pp.307-310
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• 2011

이 논문은 1년에 몇 일 혹은 몇 시간 동안 만 최대 에너지가 공급된다. 그러므로 일반적인 경우에는 대부분 최대 에너지의 50%나 이보다 적은 양의 에너지를 얻게 된다. 이런 작은량의 에너지가 공급되는 Alternative Energy system (P. Voltac System)하에서 용수공급을 위해 기존의 Centrifugal pump를 사용 할 때와 Screw type pump를 사용할 때 공급된 용수량을 비교하였다. 연구 결과 Screw type pump 사용 시 alternative Energy system의 높이에 상관없이 단지 Screw type pump의 speed에 영향을 받으며 낮은 Energy 하 에서도 비교적 높은 효율을 낸다는 것을 실험적으로 비교 검토 하였다.

• Transactions on Electrical and Electronic Materials
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• 제3권3호
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• pp.14-17
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• 2002

The HDP (High Density Plasma) CVD process consists of a simultaneous sputter etch and chemical vapor deposition. As CMOS process continues to scale down to sub- quarter micron technology, HDP process has been widely used fur the gap-fill of small geometry metal spacing in inter-metal dielectric process. However, HBP CVD system has some potential problems including plasma-induced damage. Plasma-induced gate oxide damage has been an increasingly important issue for integrated circuit process technology. In this paper, thin gate oxide charge damage caused by HDP deposition of inter-metal dielectric was studied. Multiple step HDP deposition process was demonstrated in this work to prevent plasma-induced damage by introducing an in-situ top SiH$_4$ unbiased liner deposition before conventional deposition.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.13-14
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• 2016

This paper has introduces a novel Integrated On-board Charger (IOBC) to reduce the size, weight and cost of power conversion stages in Electric Vehicles (EVs). The IOBC is composed of an OBC and a low voltage dc-dc converter (LDC). The IOBC includes a bidirectional ac-dc converter and a bidirectional full-bridge converter with an active clamp circuit. The LDC converter is a hybrid topology combining an active clamped full-bridge converter and a forward converter derived from the Weinburg converter topology. Unlike conventional OBC, the proposed IOBC is compact and the LDC converter of it can achieve a higher efficiency. In addition, the LDC converter of the proposed IOBC can achieve high step-down voltage conversion ratio, no circulating current, no reverse recovery current of the rectifier diodes and small ripple current of output inductor on the auxiliary battery. A 1kW hardware of the LDC converter is implemented to verify the performances of the proposed IOBC.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.844-855
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• 2017

Phosphate-solubilizing bacteria (PSB) have the ability to dissolve insoluble phosphate and enhance soil fertility. However, the growth and mineral phosphate solubilization of PSB could be affected by exogenous soluble phosphate and the mechanism has not been fully understood. In the present study, the growth and mineral phosphate-solubilizing characteristics of PSB strain Burkholderia multivorans WS-FJ9 were investigated at six levels of exogenous soluble phosphate (0, 0.5, 1, 5, 10, and 20 mM). The WS-FJ9 strain showed better growth at high levels of soluble phosphate. The phosphate-solubilizing activity of WS-FJ9 was reduced as the soluble phosphate concentration increased, as well as the production of pyruvic acid. Transcriptome profiling of WS-FJ9 at three levels of exogenous soluble phosphate (0, 5, and 20 mM) identified 446 differentially expressed genes, among which 44 genes were continuously up-regulated when soluble phosphate concentration was increased and 81 genes were continuously down-regulated. Some genes related to cell growth were continuously up-regulated, which would account for the better growth of WS-FJ9 at high levels of soluble phosphate. Genes involved in glucose metabolism, including glycerate kinase, 2-oxoglutarate dehydrogenase, and sugar ABC-type transporter, were continuously down-regulated, which indicates that metabolic channeling of glucose towards the phosphorylative pathway was negatively regulated by soluble phosphate. These findings represent an important first step in understanding the molecular mechanisms of soluble phosphate effects on the growth and mineral phosphate solubilization of PSB.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.340-346
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• 2002

The purpose of the present study was to examine the efficacy and mechanism of the PAB (para-amino benzamidine) affinity column chromatography, Viresolve NFP virus filtration, pasteurization (60$\^{C}$ heat treatment for 10 h), and lyophilization steps employed in the manufacture of urokinase from human urine as regards the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and subjected to scale-down processes mimicking the manufacture of urokinase Samples were collected at each step, immediately titrated using a 50% tissue culture infectious dose (TCID$\_$50/), and the virus reduction factors evaluated. PAB chromatography was found to be an effective step for removing HAV with a log reduction factor of 3.24. HAV infectivity was rarely detected in the urokinase fraction, while most of the HAV infectivity was recovered in the unbound and wash fractions. HAV was completely removed during the Viresolve NFP filtration with a log reduction factor of $\geq$ 4.60. Pasteurization was also found to be an effective step in inactivating HAV where the titers were reduced from an initial titer of 7.18 log$\_$10/ TCID$\_$50/ to undetectable levels within 10 h of treatment. The log reduction factor achieved during pasteurization was $\geq$ 4.76. Lyophilization revealed the lowest efficacy for inactivating HAV with a log reduction factor of 1.48. The cumulative log reduction factor was $\geq$ 14.08. Accordingly, these results indicate that the production process for urokinase exhibited a sufficient HAV reducing capacity to achieve a high margin of virus safety.

• 한국군사과학기술학회지
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• 제27권1호
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• pp.43-50
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• 2024

Large planar military antenna boasts a range of electrical components, including TRA(Transmit-Receive Assembly), signal processors, etc. which engage in computations and calculations. These processes generate a significant amount of heat, leading to unforeseen consequences for the equipment. To mitigate these adverse effects, it's imperative to implement a cooling system that can effectively reduce heat-related issues. Given the antenna's intricate nature and the multitude of components it houses, a two-step estimation process is necessary. The first step involves a comprehensive model calculation to determine the total flow characteristics, while the second step entails a thermal analysis of individual TRA set. In this study, we depicted an antenna set using simplified 3D models of its components, considering their material and thermal properties. The sequential analysis process facilitated the calculation of branched flow rates, providing insights into the individual TRA. This approach also allowed us to design a cooling system for the TRA set, assessing its thermal stability in high-temperature environments. To ensure the optimal performance of TRA, breaking down the analysis into stages based on the cooling system's structure can assist operators in predicting numerical results more effectively.