• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1028-1037
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• 2015

Unique organoleptic characteristics such as rich flavors and chewy texture contribute to the higher popularity of native chicken in many Asian areas, while the commercial broilers are well-accepted due to their fast-growing and higher yields of meat. Sensory attributes of foods are often used to evaluate food eating quality and serve as references during the selection of foods. In this study, a three-phase descriptive sensory study was conducted to evaluate the sensory attributes of commercial broiler (BR) and Taiwan native chicken (TNC) breast meat, and investigate correlations between these sensory attributes and instrumental measurements. The results showed that for the first bite (phase 1), TNC meat had significantly higher moisture release, hardness, springiness, and cohesiveness than BR meat. After chewing for 10 to 12 bites (phase 2), TNC meat presented significantly higher chewdown hardness and meat particle size, whereas BR meat had significantly higher cohesiveness of mass. After swallowing (phase 3), TNC meat had higher chewiness and oily mouthcoat and lower residual loose particles than BR meat. TNC meat also provided more intense chicken flavors. This study clearly demonstrates that descriptive sensory analysis provides more detailed and more objectively information about the sensory attributes of meats from various chicken breeds. Additionally, sensory textural attributes vary between BR and TNC meat, and are highly correlated to the shear force value and collagen content which influence meat eating qualities greatly. The poultry industry and scientists should be able to recognize the sensory characteristics of different chicken meats more clearly. Accordingly, based on the meat's unique sensory and physicochemical characteristics, future work might address how meat from various breeds could best satisfy consumer needs using various cooking methods.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.23-28
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• 2012

The LPG engine technology in Korea has made significant advances with the mass production of LPG vehicle with liquid phase LPG injection system, and have reached to satisfy the SULEV emission regulations. As of now, domestic production of LPG fuelled vehicles in Korea have reached more than 2.4 millions, which is the best in the world. But in the technical point of view, the key technologies for fuel injection system of LPG fuelled engine are mainly dependent on foreign license. Especially, fuel injector in the liquid phase LPG injection system has been imported from C company, which supplies LPG injector worldwide in the name of model D. In the context, it is quite urgent to develop the LPG injector technology in Korea. In this study, WCC coating which is key technology to develop LPG injector by reducing the fuel leakage was developed and tested. Considering the fuel leakage of 0.06cc/min in commercial LPG injector, fuel leakage was reduced down to 0.04cc/min with WCC coating technology and optimization of injector structure.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.5
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• pp.1-8
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• 2009

Photobioreactor (PBR) that houses and cultivates microalgae providing a suitable environment for its growth, such as light, nutrients, CO2, heat, etc. is now getting more popular in the last decade. Among the many types of PBRs, the bubble column type is very attractive because of its simple construction and easy operation. However, despite the availability of these PBRs, only a few of them can be practically used for mass production. Many limitations still holdback their use especially during their scale-up. To enlarge the culture volume and productivity while supplying optimum environmental conditions, various PBR structures and process control are needed to be investigated. In this study, computational fluid dynamics (CFD) was economically used to design a bubble-column type PBR taking the place of field experiments. CFD is a promising technique which can simulate the growth and production of microalgae in the PBR. To study bubble column PBR with CFD, the most important factor is the possibility of realizing bubble. In this study, multi-phase models which are generally used to realize bubbles were compared by theoretical approaches and comparing in a 2D simulation. As a result, the VOF (volume of fluid) model was found to be the most effective model to realize the bubbles shape as well as the flow inside PBR which may be induced by bubble injection. Considering the accuracy and economical efficiency, 0.005 second time step size was chosen for 2.5 mm mesh size. These results will be used as criteria for scale-up in the PBR simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.5
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• pp.791-798
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• 2020

The share of advanced technology in modern weapon systems are gradually increasing, and life cycle of components are shortened due to the rapid speed of technological development. On the other hand, the weapon systems have a characteristic that takes a long time in the requirement stage of weapon to the operation and maintenance stage. Due to inevitably, obsolescence of the main components for parts occurs in the acquisition phase. The obsolescence parts could cause delays in mass production schedules, and further adversely affects operational availability due to poor supply of repair parts during in the maintenance phase. However, business managers are obliged to maximize the performance while minimizing the cost of the total life cycle of the design, production, and operation stages. It is necessary to establish and implement an appropriate components and parts of life cycle management plan. In this research, we analyzed the effectiveness of parts obsolescence management through cost avoidance and total life cycle cost that can be reduced through proper parts obsolescence management.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.267-267
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• 2010

The structural and electrical properties of microcrystalline silicon films were investigated by hot wire chemical vapor deposition(HWCVD) often called catalytic chemical vapor deposition(Cat-CVD). The Si microcrystalline phase is easily controlled by changing the rate of the silane concentration of $SiH_4$ to $H_2$ during deposition. The Structural property was observed by Raman and SEM. Photo-conductivity and dark conductivity, and photo-sensitivity were observed by Sunsimulator (AM 1.5 illumination). The film color was changed by the variation of silane concentration. HWCVD is useful for the formation of Si thin films for solar cell and needs further commercialized development for mass production.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.224-229
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• 2016

Recently, polymeric micro-fluidic biochips with numerous micro patterns on the surface were fabricated by injection molding for realizing low-cost mass production of devices. To evaluate the effects of process parameters on large-scale micro-structure replication, a $50{\times}50mm^2$ tool insert with surface structures having a patterns of trapezoidal shapes (height: $30{\mu}m$) was employed. During injection molding, PMMA was used; packing phase parameters and mold temperature were investigated. The replicated surface textures were quantitatively characterized by confocal laser microscopy with 10-nm resolution. The degree of replication at low mold temperatures was found to be higher than that at high mold temperature at the beginning of the packing stage. Thereafter, the degree of replication increased to a greater extent at higher mold temperatures; application of higher mold temperatures improved the degree of replication.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4337-4340
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• 2011

The vitamin D receptor binding peptide, VDRBP, was overexpressed as a fused form with the ubiquitin molecule in Rosetta(DE3)pLysS, a protein production strain of Escherichia coli harboring an induction controller plasmid. The fusion protein was bound to the immobilized metal ions, and the denaturation and renaturation of the fusion protein were performed as a part of the purification procedure. After the elution of the fusion protein, the peptide hormone was released from its fusion partner by using yeast ubiquitin hydrolase (YUH), and subsequently purified by reverse phase chromatography. The purity of the resulting peptide fragment was checked by MALDI-TOF mass and NMR spectroscopy. The final yields of the target peptide were around 5 and 2 mg per liter of LB and minimal media, respectively. The recombinant expression and purification of this peptide will enable structural and functional studies using multidimensional NMR spectroscopy and X-ray crystallography.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.223-226
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• 2004

Injection molding using plastic materials was expected to mass production of structure with nano pattern for low cost phase. The PDMS mold was produced easily and uniformly by using thermal embossing. Quartz master for embossing method was made using electron beam lithography it had 100-500 nm size of line and dot type. The PDMS mold was produced after a brief hardening process and the master removal. The results show that various patterns are successfully fabricated the nano scale.. The replicated mold would be useful a stamper fabrication for injection molding.

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.244-251
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• 1993

A novel system has been developed to produce ${\delta}-aminolevulinic$ acid (ALA) using the intact cells of late logarithmic phase of Rhodocyclus gelatinosus KUP-74. The system was shown optimum yield of extracellular ALA under a condition of anaerobic light irradiation (4 Klux) at $30^{\circ}C$ with no variation in cell mass. The rate of extracellular ALA formation was stimulated by low doses of either $C_4\;or\;C_5$ ALA biosynthetic precursors, where 5 mM ($C_4) and 3 mM ($C_5) of each precursors were appeared to generate the maximum rates of 3.3 and 4.0 nmoles of ALA per 0.35 mg cells per hr, respectively. Half-life of the system was 10 hr in a sense of an ability of portage transport of L-glutamate, and sequential dose of this compound was resulted in promising recovery of the ALA.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.581-585
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• 2005

The antimicrobial activity of partially purified enterocin K25, produced by Enterococcus sp. K25, was abolished by proteases such as pepsin and proteinase K. The bacteriocin was resistant to heat treatment at $75^{\circ}C$ for 15 min and lost 75% of its activity at $100^{\circ}C$ for 30 min. Enterocin K25 showed bactericidal mode of action against an indicator strain, Lactobacillus plantarum NCDO 955. Enterocin K25 was purified to 112.6-fold purity via conventional steps of ammonium sulfate precipitation, ion exchange chromatography, and reversed phase high performance liquid chromatography (RP-HPLC). The molecular mass of the purified enterocin K25 was estimated as 4.3 kDa on an electrophoresis gel. Plasmid (${\sim}6.5\;kb$) linkage of production of enterocin K25 was confirmed by plasmid curing.