• Journal of the Korean Wood Science and Technology
• /
• v.31 no.4
• /
• pp.31-37
• /
• 2003

Flat-sawn 32 mm-thick boards of Populus alba×P. glandulosa, one of major plantation species in this country, were dried in conventional, high-temperature and microwave-vacuum (MW/V) kilns. The average green specific gravity of the specimens used in this study was 0.349±0.074. Their average green moisture contents of heartwoods and sapwoods were around 200% and 100%, respectively. From green to oven-dry they shrunk 2.4 and 7.3% in radial and tangential directions, respectively, and there was no discrepancy between heartwoods and sapwoods. It took 65, 35 and 22 hours to dry from green to 10% moisture content in conventional, high-temperature and MW/V kilns, respectively. A colorimetry study showed that the surface color of the specimens dried in a MW/V kiln was clearer and lighter than those in other kilns.

• Textile Coloration and Finishing
• /
• v.33 no.4
• /
• pp.202-209
• /
• 2021

Natural dyes are more expensive than synthetic dyes and the dyeing process, which is mainly immersion of dye, is complicated. For this reason, relatively small-scale production methods were predominant. However, awareness and interest in environmental sustainability is rising globally, and the use of synthetic dyes causes various environmental problems such as wastewater and CO₂ emission, so the consumption of natural dyes is increasing. In addition, interest in digital textile printing, an eco-friendly dyeing method that can produce products of various designs and uses less water, is growing. In this study, natural indigo dye (Indigofera tinctoria) was used as a raw material for Digital Textile Printing ink, and ¹⁴C (Biocarbon) present in it was measured to confirm whether it was derived from natural ingredients. The performance was confirmed by testing the pH, viscosity, electrical conductivity, surface tension, and particle size analysis of natural indigo ink. In addition, the performance of natural indigo DTP ink and printing fabric was evaluated by inspecting the change in color fastness and corresponding index substances before and after digital printing with natural indigo DTP ink on textiles. Through this, the possibility of commercialization of DTP ink and printing fabric using natural indigo was confirmed.

• The Korean Journal of Food And Nutrition
• /
• v.35 no.3
• /
• pp.223-230
• /
• 2022

The purpose of this study was to examine the quality characteristics of cookies made with Angelica gigas Nakai fermented by Lactobacillus paracasei. As the content of Angelica gigas Nakai fermented by L. paracasei (AFL) powder increased, the pH of the cookies decreased from 6.3 to 5.2. There was no significant difference in the moisture content depending on AFL powder content. The content of reducing sugar also increased with increasing AFL powder content. Regarding the surface color of the cookies, the L- and b-values decreased with increasing AFL powder content, whereas the a-value increased. As the AFL powder content increased, the total polyphenol content and ABTS and DPPH radical scavenging activities significantly increased. Cookies with 8% AFL powder (AC8) had the highest levels of 107.16 mg%, 38.69%, and 65.56%, respectively. The texture, adhesiveness, and cohesiveness of the cookies with various AFL powder levels were not significantly different, and hardness, springiness, gumminess, and chewiness showed no tendencies toward changes. Taken together, these results showed that when AFL powder was added to cookies, bioactivities such as antioxidant activity increased, making AFL powder a good material with high potential for use in commercially baked products.

• Food Science of Animal Resources
• /
• v.43 no.1
• /
• pp.73-84
• /
• 2023

Campylobacteriosis is a common cause of gastrointestinal disease. In this study, we suggest a general strategy of applying gold nanoparticles (AuNPs) in colorimetric biosensors to detect Campylobacter in chicken carcass. Polymerase chain reaction (PCR) was utilized for the amplification of the target genes, and the thiolated PCR products were collected. Following the blending of colloid AuNPs with PCR products, the thiol bound to the surface of AuNPs, forming AuNP-PCR products. The PCR products had a sufficient negative charge, which enabled AuNPs to maintain a dispersed formation under electrostatic repulsion. This platform presented a color change as AuNPs aggregate. It did not need additional time and optimization of pH for PCR amplicons to adhere to the AuNPs. The specificity of AuNPs of modified primer pairs for mapA from Campylobacter jejuni and ceuE from Campylobacter coli was activated perfectly (C. jejuni, p-value: 0.0085; C. coli, p-value: 0.0239) when compared to Salmonella Enteritidis and Escherichia coli as non-Campylobacter species. Likewise, C. jejuni was successfully detected from artificially contaminated chicken carcass samples. According to the sensitivity test, at least 15 ng/μL of Campylobacter PCR products or 1×10³ CFU/mL of cells in the broth was needed for the detection using the optical method.

• Journal of the FoodService Safety
• /
• v.4 no.1
• /
• pp.7-20
• /
• 2023

This study was conducted to investigate the impact of refrigerator type and temperature fluctuations on the quality changes of refrigerated foods. Phycochemical and sensory quality, as well as microbial growth, were measured for various foods stored in open- or door-type refrigerators set at 5℃ during storage. The average temperatures recorded were 11.50±1.14℃ in an open refrigerator, and 6.34±0.97℃ in a closed refrigerator. The average surface temperatures of the food items were 9.60±1.20 and 6.00±0.80℃ for open and closed refrigerators, respectively. Significant changes in color and appearance quality were observed in lettuce, mackerel, ground beef, and cut pineapples when stored in open refrigerators. Ready-to-Eat foods such as gimbap and sandwiches exhibited higher levels of microbiological proliferation when stored in open refrigerators compared to closed refrigerators. Processed foods, such as sterilized milk and packaged tofu, did not show significant differences in quality among various types of refrigerators. The installation of refrigerator doors can effectively minimize temperature fluctuations caused by external factors, thereby reducing variations in food quality. These findings provide essential insights into the quality changes associated with the implementation of refrigerator doors, serving as fundamental data for ensuring optimal food preservation.

• Korean Journal of Materials Research
• /
• v.32 no.3
• /
• pp.125-131
• /
• 2022

Effect of sulfation processes on the physicochemical properties of ZrO₂ and TiO₂ nanoparticles were thoroughly investigated. SO₄/ZrO₂ and SO₄/TiO₂ catalysts were synthesized to identify the acidity character of each. The wet impregnation method of ZrO₂ and TiO₂ nanoparticles was employed using H2SO₄ with various concentrations of 0.5, 0.75, and 1 M, followed by calcination at 400, 500, and 600 ℃ to obtain optimum conditions of the catalyst synthesis process. The highest total acidity was found when using 1 M SO₄/ZrO₂-500 and 1 M SO₄/TiO₂-500 catalysts, with total acidity values of 2.642 and 6.920 mmol/g, respectively. Sulfation increases titania particles via agglomeration. In contrast, sulfation did not practically change the size of zirconia particles. The sulfation process causes color of both catalyst particles to brighten due to the presence of sulfate. There was a decrease in surface area and pore volume of catalysts after sulfation; the materials' mesoporous structural properties were confirmed. The 1 M SO₄/ZrO₂ and 1 M SO₄/TiO₂ catalysts calcined at 500 ℃ are the best candidate heterogeneous acid catalysts synthesized in thus work.

• Journal of Convergence for Information Technology
• /
• v.12 no.2
• /
• pp.149-156
• /
• 2022

In this paper, it was attempted to form a titanium (Ti: Titanium) thin film using the atmospheric pressure plasma process technology for the conductor, which is the main component of the optical sensor. The atmospheric plasma equipment was remodeled. A 4-inch Ti target for sputter was etched using CF4 gas, and the by-product was coated on a glass sample. These by-products were formed up to about 2 cm, and could be divided into 15 areas according to color. Surface shape and constituent elements were analyzed using scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), respectively. Electrical properties using 4-point probe equipment were also measured. If the process is performed by positioning the sample at about 4.5 mm to 5 mm from the target, a uniform Ti thin film will be deposited. However, it was found that the thin film contained a significant amount of fluorine, which greatly affects the electrical properties of the thin film. Therefore, additional experiments and studies should be performed to remove or minimize fluorine during deposition.

• Design Convergence Study
• /
• v.15 no.6
• /
• pp.229-241
• /
• 2016

In generative design computer automatically and quickly generates many alternative design solutions, and the computer algorithms which perform the design tasks are important. The main purpose of this study is to propose a computer algorithm which generates three-dimensional shapes from a two-dimensional digital image such as a photograph or a painting. The base geometry of the final shape is a cylinder or sphere. A surface of the cylinder or sphere is deformed depending on the used image. The proposed algorithm was implemented as a computer program, and the program tested with several famous paintings. The algorithm and results presented in this study implicate the possibilities of the generative design which generates three-dimensional shapes from two-dimensional images. It is necessary to find and measure the values of the generated shape, and it will be a future research to find the relations of emotional and cognitive aspects between the input images and the generated shapes. Those studies are expected to expand the possibilities of generative design.

• Clinical Endoscopy
• /
• v.56 no.3
• /
• pp.315-324
• /
• 2023

Background/Aims: Image-enhanced endoscopy can detect superficial oro-hypopharyngeal squamous cell carcinoma; however, reliable endoscopy of the pharyngeal region is challenging. Endoscopy under general anesthesia during transoral surgery occasionally reveals multiple synchronous lesions that remained undetected on preoperative endoscopy. Therefore, we aimed to determine the lesion detection capability of endoscopy under general anesthesia for superficial oro-hypopharyngeal squamous cell carcinoma. Methods: This retrospective study included 63 patients who underwent transoral surgery for superficial oropharyngeal squamous cell carcinoma between April 2005 and December 2020. The primary endpoint was to compare the lesion detection capabilities of preoperative endoscopy and endoscopy under general anesthesia. Other endpoints included the comparison of clinicopathological findings between lesions detected using preoperative endoscopy and those newly detected using endoscopy under general anesthesia. Results: Fifty-eight patients (85 lesions) were analyzed. The mean number of lesions per patient detected was 1.17 for preoperative endoscopy and 1.47 for endoscopy under general anesthesia. Endoscopy under general anesthesia helped detect more lesions than preoperative endoscopy did (p<0.001). The lesions that were newly detected on endoscopy under general anesthesia were small and characterized by few changes in color and surface ruggedness. Conclusions: Endoscopy under general anesthesia for superficial squamous cell carcinoma is helpful for detecting multiple synchronous lesions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.11
• /
• pp.5350-5355
• /
• 2012

Human tyrosinase (hTyr) catalyzes the first and rate limiting step in the biosynthesis of a skin color determinant, melanin. Although a number of cosmetic companies have tried to develop hTyr inhibitors for several decades, absence of 3D structure of hTyr make it impossible to design or screen inhibitors by structure-based approach. Therefore, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from Bacillus megaterium to provide structural information and to search new hit compounds from database. Our model revealed that two copper atoms of active site located deep inside and were coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Substrate binding site had narrow funnel like shape and its entrance was wide and exposed to solvent. In addition, hTyr-tyrosine and hTyr-kojic acid, a well-known inhibitor, complexes were modeled with the guide of solvent accessible surface generated by in-house software. Our model demonstrated that only phenol group or its analogs could fill the binding site near the nuclear copper center, because inside of binding site had narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogenic agents.