• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1729-1730
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• 2006

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.66-68
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• 2003

Polycyclic Aromatic Hydrocarbons (PAHs) are hydrophobic and most are practically insoluble in water contributing to their persistence in the environment. In addition, most exist in strongly adsorbed forms when they are introduced into the soils. Their removal efficiency can be limited in low mass transfer phases, such as PAHs-contaminated soils, because most chemical and biological remediation technologies require transfer from NAPs (Non-Aqueous Phase Liquids) into the mobile phase. (omitted)

• 연구논문집
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• s.24
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• pp.151-159
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• 1994

The heat transfer and thermal stress analysis was performed on the ceramic core of the matrix-type recuperator. The efficiency was calculated as 34% to 65%. Triple-pass arrangement provided higher preheated air temperatures, lower thermal stresses and the increase of pressure drops. Higher temperature gradients and maximum peak stresses appeared on the corners of the ceramic core. The effect of boundary conditions was significant and the use of spring-load sealing mechanism could release thermal stresses.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.185-189
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• 2016

Energy-saving heat depending on the country's rise in oil prices up to the product development is regarded as pending issues. Therefore, in recent years, been a continuing research studies developed for increasing the economic efficiency and reliability achieved in effectively using the side of the energy for heating using electrical to address these problems and, in particular made active the technology developed for high performance and renal material becoming. This paper is to study the development of highly efficient induction heating device according to the excellent heat transfer characteristics for energy transfer. Induction heating is used as the phenomenon of electromagnetic induction, such as heat transfer conduction or convection of the existing methods are no different. Medium heat without beating is absorbed directly into the water column switched rapidly, have features that heats evenly. In addition, high-frequency induction heating in a variety of frame designs. Heating element heats only when utilized properly, it is possible to heat the focus.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.793-799
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• 2016

In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

• Korean Journal of Microbiology
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• v.47 no.1
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• pp.1-6
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• 2011

Inefficiency of in vivo gene transfer using currently available vectors reflects a major hurdle in cancer gene therapy. Both viral and non-viral approaches have been described to improve gene transfer efficiency but suffer from a number of limitations. Here we tested an adenovirus carrying the small peptide ligand derived from heregulin${\beta}$ EGF-like domain onto fiber, the adenoviral capsid protein, to deliver transgene to ovarian cancer cells which overexpress ErbB, the cognate receptors for heregulin. The attachement of 53 amino acids to fiber didn't affect on the fiber's trimer structure that is critical for the viral entry to cells. The fiber-modified adenovirus can mediate entry and expression of a ${\beta}$-galactosidase into cancer cells in an increased efficiency compared the unmodified adenovirus. Particularly, the gene transfer efficiency was improved up to 5 times in OVCAR3 cells, an ovarian cancer cell line. Such transduction systems hold promise for delivering genes to ErbB receptor overexpressing cancer cells, and could be used for future cancer gene therapy.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.81-87
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• 2008

Production of transgenic animals for studying specific gene has been limited due to a low efficiency, lack of skilled researchers and the need for expensive equipment. Currently, the boar spermatozoa as a vector to deliver exogenous DNA into the oocyte were used to improve the efficiency of transfection rate. In this study, we revealed that the optimal conditions for DNA uptake in spermatozoa by liposome were to 90 min of incubation, $17^{\circ}C$, $10^5$ spermatozoa, 4 ng/ml of exogenous DNA and 0.5% (v/v) liposome, without damage to fertility. In addition, the developmental rate to the blastocyst stage of embryo in control group was significantly higher than those embryos with exogenous DNA and liposome, whereas there were no significant differences in embryo development between the liposome and type of DNA. The transfection rates of embryo using treated spermatozoa with both liposome and circular DNA were higher than those using linear DNA. These findings raise the possibility thattreated spermatozoa with liposome/DNA complexes could be used in in vitro fertilization, and the exogenous DNA transferred into the oocytes. Taken together, we demonstrated that liposome a vector for the uptake of exogenous DNA in boar spermatozoa could improve the efficiency of sperm-mediated gene transfer in creating transgenic pig and the other domestic transgenic animals.

• The Journal of the Acoustical Society of Korea
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• v.15 no.6
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• pp.52-58
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• 1996

Using the acoustic resonances and oscillatory pulsations considered as the branch of wave technologies, the concept of the acoustic resonance diffusers for waste water treatment which maximize the oxygen transfer efficiency in gas-liquid two phase medium have been proposed, and studies for the principles and performance tests were accomplished. Besides, the design concepts for the low pressure Helmholtz resonator, cylinder and annular type reflection resonator and combined type resonance system have been implemented. The acoustic resonance energy which can speed up the mass transfer process increase the oxygen transfer efficiency, and periodic pulsations generated from the instability of air jet from nozzle make very small air bubbles. Then, the annular type jet resonator(AJR) applying these two principles successfully was evalulated as the most promising device and also the efficiency showing $20{\sim}30%$ better than conventional diffusers has been verified experimentally.

• Journal of Aquaculture
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• v.8 no.3
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• pp.241-249
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• 1995

Sperm from mud loach (Misgurnus mizolepis) were electroporated in the presence of plasmid DNA, pRSV/luc or pMT/hGH over a range of field strength of 0-1,625 V/cm with capacitance from 0 to 1,000 ${\mu}F$, and the effects of electroporation on fertilization, hatching, early survival, and efficiency of gene transfer were investigated. Average fertilization rate, hatching rate and early survival rate up to yolk sac absorption of all experimental groups were not significuntly different (P>0.05). The proportion of fish carrying pRSV/luc based on the polymerase chain reaction (PCR) analysis was ranged from 0 to $20\%$, however, the values of gene transfer efficiency from the different eledctroporation conditions were not significantly different. PCR analysis of pMT/hGH transferred groups revealed that screening of pMT/hGH transferred fish by PCR was difficult because of significant nonspecific amplifications resulted from the homologous sequences in the genome of mud loach.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.43-49
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• 2015

In this paper, we propose enhanced wireless power transfer system based on magnetic resonance for portable electronic device charging. Resonators were designed and fabricated for efficiency improvement and miniaturization through electromagnetism simulation using HFSS(High Frequency Structure Simulator). Impedance matching network is employed to minimize reflections that is caused by difference between input impedance and output impedance. Receiver IC that consist of rectifier and Low Drop Out(LDO) regulator were designed and fabricated to reduce power loss. This chip is implemented in $0.35{\mu}m$ BCD technology. A maximum overall efficiency of 73.8% is determined for the system through experimental verification.