• Design & Manufacturing
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• v.17 no.3
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• pp.55-60
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• 2023

The fiber-reinforced plastics and cellular injection molding process can be used to efficiently reduce the weight of battery housing components of mild hybrid electronic vehicles(MHEV) made of metal. However, the fiber orientation of fiber-reinforced plastics and the growth of foaming cells are intertwined during the injection molding process, so it is difficult to predict the mechanical properties of products in the design process. Therefore, it is necessary to evaluate the mechanical properties of the materials prior to the efficient stiffness design of the target product. In this study, a study was conducted to evaluated the mechanical properties of fiber reinforced cellular injection-molded specimens. Two types of fiber-reinforced plastics that can be used in the target product were evaluated for changes in tensile properties of cellular injection-molded specimens depending on the foaming ratio and position from the injection gate. The PP and PA66 specimens showed a decrease of tensile modulus and strength of approximately 30% and 17% depending on the foaming ratio, respectively. Also, the tensile strength decreased approximately 26% and 17% depending on the position from the injection gate, respectively. As a result, it was confirmed that the PP specimens have a significantly mechanical property degradation compared to the PA66 specimens depending on the foaming ratio and position.

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• v.9
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• pp.431-441
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• 2021

Gadolinium-doped ceria (GDC) is sought-after as an electrolyte layer in solid oxide fuel cells because of its high ionic conductivity and low treatment temperature. Recently, some studies have been reported to produce a component layer of solid oxide fuel cell using a Roll-to-Roll (R2R) system because of its characteristics of the cost-effective and eco-friendly advantages. However, the brittleness and low density of GDC prevent it from being mass-produced via the R2R continuous process. Therefore, we attempted to improve the density of GDC-based multi-electrolyte layers through an optimized R2R calendaring process. The finite element method was employed to determine suitable materials for the calendering rolls and the maximum calendering pressure that would reduce the thickness and porosity of the coated electrolyte layer without producing cracks in the layer. The effect of the number of calendering processes on the thickness and porosity of the electrolyte layers was examined as well. Silicon and steel were observed to be best-suited as the materials for the top and bottom rolls, respectively. Moreover, the maximum permissible calendering pressure was determined to be 15 MPa, while the ideal number of calendering processes was found to be 5. Experimental observations using scanning electron microscopy confirmed that the optimized calendering process reduced the thickness and porosity of the coated electrolyte layers by 16.99% and 7.04%, respectively. Thus, our findings suggest that large-area, high-density GDC-based multi-electrolyte layers with smooth surfaces can be produced via the R2R process, which can enable mass production of SOFCs.

• Design & Manufacturing
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• v.18 no.3
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• pp.1-8
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• 2024

Macular degeneration is a disease that damages the macula, the center of the retina, and is one of the three major eye diseases along with glaucoma and diabetic retinopathy. The optic nerve and most of the photoreceptor cells are located here, and since this is where images of objects are formed, it is the most important area for vision. The main symptom of macular degeneration is the inability to clearly distinguish the shape of objects or the inability to distinguish colors and light and dark. It is also a serious eye disease that causes black spots in the center of the field of vision. However, it is difficult to distinguish it from the form of vision loss due to presbyopia, so early diagnosis is often missed. The most common treatment for macular degeneration is antibody injection therapy. This treatment requires regular injections once every 1-2 months. When receiving antibody injection therapy, the fear of having to inject directly into the eye and the cost of long-term repeated procedures are a great burden to patients. To overcome these problems, special sustained-release formulations using drug delivery systems are being developed. Since the release speed and release time of the drug can be controlled, the number of times the drug is administered can be drastically reduced. However, the implant (Ø 0.46×6.0mm), which is a sustained-release agent, is manufactured by mixing biodegradable resin (PLGA) and therapeutic agent in a ratio of 4:6, so it is very brittle and there is a high risk of implant damage during handling. In order to safely insert the implant into the eye, a transport device that can be driven with controlled force is required. Therefore, in this study, the lever operating force was measured and analyzed to determine the influence of factors according to the cross-sectional thickness and shape of the linkage produced through injection molding as well as the post-process.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.324-332
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• 1998

In order to standardize the chinese cabbage kimchi, the preparation method, kinds of ingredients and levels of the ingredients were determined by the statistical survey of literatures obtained from cooking books, scientific papers and kimchi manufacturing factory. The standardized ingredient kinds and ratio of chinese cabbage kimchi were $13.0{\pm}7.0$ of radish, $2.0{\pm}0.5$ of green onion, $3.5{\pm}0.8\;or\;2.5{\m}0.3$ of red pepper powder, $1.4{\pm}0.4$ of garlic, $0.6{\pm}0.3$ of ginger, $2.2{\pm}1.6$ of anchovy juice, and $1.0{\pm}0.3$ of sugar in the proportion of 100 salted chinese cabbage, and the final salt concentration was adjusted to 2.7% using salt. Red pepper powder level was quite different from the literature sources, so sensory evaluation, chemical properties and antimutagenic effect and growth inhibitory effect on human cancer cells of the kimchi samples were studied to decide the proper ratio of the red pepper powder as an ingredient. Red pepper powder 3.5% (average level for kimchi manufacturing factory) added kimchi was better in quality than red pepper powder 2.5% (average level for cooking books and scientific papers) added kimchi in sensory evaluation and chemical properties. The juice of red pepper powder 3.5% added kimchi showed not only the stronger antimutagenicity against aflatoxin $B_1$ in Salmonella typhimurium TA100 but also the higher inhibitory effect on the growth of AGS human gastric adenocarcinoma cells in SRB assay than that of red pepper powder 2.5% added kimchi. In conclusion, the standardized ratio of the ingredients was 13.0 radish, 2.0 green onion, 3.5 red pepper powder, 1.4 garlic, 0.6 ginger, 2.2 anchovy juice, 1.0 sugar, and 2.7 final salt concentration in the proportion of 100 salted chinese cabbage.

• Applied Biological Chemistry
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• v.51 no.2
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• pp.142-147
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• 2008

Nuruk is the Korean traditional Koji that contains various microorganisms and has been used to make the traditional fermented foods including alcoholic beverages. Rhizopus oryzae KSD-815 was isolated from the alcohol-fermenting Nuruk used for manufacturing traditional alcohol. In this study, the authors reported the isolation and identification of four lipids from the Nuruk (Rhizopus oryzae KSD-815) that inoculated wheat with Rhizopus oryzae KSD-815. The dried and powdered Nuruk (Rhizopus oryzae KSD-815) were extracted three times at room temperature with 80% aqueous MeOH. The extracts were partitioned with EtOAc, n-BuOH, and water, successively. The EtOAc extract was suspended in 80% MeOH and partitioned repeatedly with n-hexane. From the n-hexane fraction, four lipids were isolated through the repeated silica gel and ODS column chromatographies. According to the results of physico-chemical data including NMR, GC and MS, the chemical structures of the compounds were determined as linolenic acid methyl ester (1), palmitic acid methyl ester (2), linoleic acid (3), palmitic acid (4). Cytotoxicity was evaluated in huamn breast cancer cells, MDA-MB-231 and human hepatocarcinoma, SK-HEP-1 cells using MTT assay. Exposure of compounds 1 and 3 led to a dose-dependent inhibition of cell viability in both cancer cell lines. In addition, treatment of RAW264.7 cells with compound 3 caused inhibition of lipopolysaccharide/interferon-${\gamma}$-induced nitric oxide production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1180-1185
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• 2015

This study was performed to investigate the biological activity of yangha flower buds as well as to manufacture of yanggeng prepared with various levels (0 g, 3 g, 6 g, 9 g, and 12 g) of yangha flower buds. DPPH and ABTS scavenging activities of yangha flower buds were 96% and 57% compared to levels of vitamin C, respectively. In the oxygen radical antioxidant capacity assay, antioxidant activity increased dose dependently up to $500{\mu}g/mL$ of yangha flower buds. There was no toxicity up to $1,000{\mu}g/mL$ in vascular smooth muscle cells, and yanggeng significantly reduced migration and proliferation by platelet-derived growth factor-BB-stimulated rat aortic smooth muscle cell migration and proliferation. In the sensory evaluation, the optimal sample was YY9, which was prepared with 9 g of yangha flower buds. It can be concluded that yangha flower buds show antioxidant and vascular protective activities. The optimal sample (YY9) is expected to contribute as a new functional food.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.267-274
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• 2015

Biopharmaceuticals and the cell substrates used for their manufacture are currently tested for porcine adventitious viruses due to the widespread use of porcine trypsin in cell culture. Porcine transmissible gastroenteritis virus (PTGV) is one of the major adventitious porcine viruses causing contaminated during the manufacture of biopharmaceuticals. Therefore, rapid and sensitive detection of PTGV is essential in ensuring the safety of biopharmaceuticals. A TaqMan probe real-time RT-PCR method was developed for the quantitative detection of PTGV contamination in cell substrates, raw materials, manufacturing processes, and final products, as well as PTGV clearance validation. Specific primers for the amplification of PTGV RNA were selected, and PTGV RNA was quantified by use of a specific TaqMan probe. Specificity, limit of detection (LOD), and robustness of the method was validated according to international guidelines on the validation of nucleic acid amplification tests. The sensitivity of the assay was calculated to be 1.10 × 10⁰ TCID₅₀/ml. The real-time RT-PCR method was validated to be reproducible, very specific to PTGV, and robust. The established real-time RT-PCR assay was successfully applied to the validation of Chinese Hamster Ovary (CHO)-K1 cells artificially infected with PTGV.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.12-20
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• 2008

Validation of viral safety is essential in ensuring the safety of mammalian cell culture-derived biopharmaceuticals, because numerous adventitious viruses have been contaminated during the manufacture of the products. Mammalian cells are highly susceptible to minute virus of mice(MVM), and there are several reports of MVM contamination during the manufacture of biopharmaceuticals. In order to establish the validation system for the MVM safety, a real-time PCR method was developed for quantitative detection of MVM in cell lines, raw materials, manufacturing processes, and final products as well as MVM clearance validation. Specific primers for amplification of MVM DNA was selected, and MVM DNA was quantified by use of SYBR Green I. The sensitivity of the assay was calculated to be $6{\times}10^{-2}TCID_{50}/mL$. The real-time PCR method was proven to be reproducible and very specific to MVM. The established real-time PCR assay was successfully applied to the validation of Chinese hamster ovary (CHO) cell artificially infected with MVM. MVM DNA could be Quantified in CHO cell as well as culture supernatant. When the real-time PCR assay was applied to the validation of virus removal during a virus filtration process, the result was similar to that of virus infectivity assay. Therefore, it was concluded that this rapid, specific, sensitive, and robust assay could replace infectivity assay for detection and clearance validation of MVM.

• Applied Biological Chemistry
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• v.49 no.1
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• pp.55-59
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• 2006

This study was designed to investigate the optimum manufacturing condition of germanium-fortified yeast, and the binding properties of germanium (Ge) in germanium-fortified yeast. The nutritional optimum conditions were glucose 3.0 (w/v) %, yeast extracts 0.3 (w/v) % and peptone 0.5 (w/v) %, and the amounts of yeast cells were 67.4 mg/ml. And, the standard germanium-fortified yeast was produced under the condition at the ratio of yeast cell and germanium solution was 1 : 0.5 (50%), pH 6.5 and $35-40^{\circ}C$ during fermentation. In results of the identification, binding of germanium-protein showed structural difference between the inorganic Ge $(GeO_2)$ added during fermentation process and germanium-fortified yeast. Therefore, germanium-fortified yeast made by biosynthetic technology formed structurally safe organic germanium during fermentation process. Germanium-fortified yeast can be applied as a new functional material far the improvement of health, the prevention and treatment of chronic degenerative disease like cancer, and the enforcement of immune system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.644-653
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• 2018

Landslides occur frequently due to the effects of heavy rainfall and typhoons caused by climate change. Erosion control measures are needed to effectively prevent landslide damage. In order to improve their efficiency, it is necessary to quantitatively measure the sediment discharge from the mountain stream. In this study, a load cell sensor was installed in a mountain stream and the measured values were compared according to the applicability and load test type in the mountain stream. The result of the load test showed that the effect of the loading type (load test 1, 2) was low at average (loadings) of 0.4kgf and 0.6kgf at sites 1 and 2, respectively. The load factor was also derived by regression analysis to increase the accuracy of the measured values. According to the results of the load factor (normalized) to the load-cell measurement value, the output value increased by 14.8% and 24.6% in sites 1 and 2, respectively, and was calculated to be similar to the reference value. The load cell sensor enabled us to quantitatively estimate the amount of sediment discharge in the mountain stream through time series analysis with the water level and rainfall information. If the monitoring is carried out for a long time, it can be used to find the sediment discharge mechanism for the mountain stream. In addition, applying sensors such as load-cells to a mountain stream is expected to contribute to the development of related industries, such as the manufacturing of measurement sensors.