• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.640-647
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• 2023

Material corrosion in nuclear power plant (NPP) is not controlled only by amine injection but also by ion exchange (IX) which is the best option to remove trace Na⁺. This study was conducted to understand the Na⁺ leakage characteristics of IX beds packed with ethanolamine-form (ETAH-form) and hydrogen-form (H-form) resins in the simulated water-steam cycle in terms of intrinsic behaviors of four kinds of cation-exchange resins through ASTM test and Vanselow mass action modeling. Na⁺ was inappreciably escaped throughout the channel created in resin layer. Na⁺ leakage from IX bed was non-linearly raised because of its decreasing selectivity with increasing Na⁺ capture and with increasing the fraction of ETAH-form resin. Na⁺ did not reach the breakthrough earlier than ETAH⁺ and NH₄⁺ due to the increased selectivity of Na⁺ to the cation-exchange resin (H⁺ < ETAH⁺ < NH₄⁺ ≪ Na⁺) at the feed composition. Na⁺ leakage from the resin bed filled with small particles was decreased due to the enhanced dynamic IX processes, regardless of its low selectivity. Thus, the particle size is a predominant factor among intrinsic properties of IX resin to reduce Na⁺ leakage from the condensate polishing plant (CPP) in NPPs.

• Phonetics and Speech Sciences
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• v.16 no.2
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• pp.49-58
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• 2024

This study aimed to compare the acoustic measurements of speech samples recorded from individuals with normal voices using various devices: the Computerized Speech Lab (CSL), a unidirectional wired pin-microphone (WIRED) suitable for smartphones, the built-in omnidirectional microphone (SMART) of smartphones, and Bluetooth-connected wireless earphones, specifically the Galaxy Buds2 Pro (WIRELESS). This study included 40 normal adults (12 males and 28 females) who had not visited an otolaryngologist for respiratory diseases within the past three months. Participants performed sustained vowel /a/ phonation for four seconds and reading tasks with sentences ("Walk") and paragraphs ("Autumn") in a sound-treated booth. Recordings were simultaneously conducted using the four different devices and synchronized based on the CSL-recorded samples for analysis using the MDVP, ADSV, and VOXplot programs. Compared with CSL, the Cepstral Spectral Index of Dysphonia (CSID_V, CSID_S) and Acoustic Voice Quality Index (AVQI) values were lower in the WIRED and higher in the SMART. The opposite trend was observed for the L/H spectral ratios (SR_V and SR_S), and the WIRELESS demonstrated task-specific discrepancies. Furthermore, both the fundamental frequency (F0) and the cepstral peak prominence of the vowel samples (CPP_V) had intraclass correlation coefficient (ICC) values above 0.9, indicating high reliability. These variables, F0 and CPP_V were considered highly reliable for voice recordings across different microphone types. However, caution should be exercised when analyzing and interpreting variables such as the SR, CSID, and AVQI, which may be influenced by the type of microphone used.

• The Journal of the Acoustical Society of Korea
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• v.43 no.4
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• pp.422-435
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• 2024

This study intended to verify the effects of face masks on the Korean language in terms of acoustic, aerodynamic, and formant parameters. We chose all types of face masks available in Korea based on filter performance and folding type. Two professional voice actors (a male and a female) with more than 20 years of experience who are native Koreans and speak standard Korean participated in this study as speakers of voice data. Face masks attenuated the high-frequency range, resulting in decreased Vowel Space Area (VSA) and Vowel Articulation Index (VAI)scores and an increased Low-to-High spectral ratio (L/H ratio) in all voice samples. This can result in lower speech intelligibility. However, the degree of increment and decrement was based on the voice characteristics. For female speakers, the Speech Level (SL) and Cepstral Peak Prominence (CPP) increased with increasing face mask thickness. In this study, the presence or filter performance of a face mask was found to affect speech acoustic parameters according to the speech characteristics. Face masks provoked vocal effort when the vocal intensity was not sufficiently strong, or the environment had less reverberance. Further research needs to be conducted on the vocal efforts induced by face masks to overcome acoustic modifications when wearing masks.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.21-25
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• 1997

Application of the color indicators to kimchi packages was investigated in order to monitor the ripeness of commercial kimchi products during storage and distribution. Kimchi was packed in polypropylene (PP) tray and nylon/cast polypropylene (Ny/CPP) lid where the indicating sachet consisting of $CO_2$ absorbent and chemical dye (bromocresol purple and methyl red) was attached. The ripeness of kimchi during storage at $0{\sim}20^{\circ}C$ was measured in terms of pH and titratable acidity (TA), which were compared with Hunter color values of the indicators. The color of bromocresol purple dye turned from light blue to purple, while that of methyl red turned from light yellow to red. Regardless of the storage temperatures, Hunter b values of bromocresol purple type and Hunter a values of methyl red type appeared to be proportional to both the pH and TA values of kimchi. These results suggest that the color indicators be employed as one of the effective techniques for sensing the ripeness of packaged kimchi products without destructing the package.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.461-469
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• 2010

Polyurethane adhesive is used in various fields as flexible packaging materials including a food packaging field. Therefore, the purpose of this study is synthesis of polyurethane adhesive which uses aliphatic isocyanate, and compares with aromatic isocyanate. The isocyanates for this test are toluene-2,4-diisocyanate(TDI), hexamethylene diisocyanate(HDI), 4,4-dicyclohexyl ethane diisocyanate($H_{12}MDI$), and isophorone diisocyanate(IPDI). And, the effect of any other diisocyanate are evaluated by several methods as for curing rate test, accelerate weathering test, and peel strength test. The polyurethane adhesive using curing catalyst and HDI has adhesion strength of about 560 g/15 mm between aluminium foil and nylon, about 1,520 g/15 mm between nylon and CPP. Those parameters are similar to polyurethane adhesive with TDI. Also, in case of curing rate, those are similar to TDI type polyurethane adhesive. Moreover, data of ${\Delta}E$ as color variation by QUV tester is equal to 4.12, as 48% against those of TDI type.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1326-1330
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• 2000

Kimchi, made from seasonal baechu (Chinese cabbage), was sealed in PP trays with a Nylon/CPP lid film and stored at various temperatures (0, 10, $20^{\circ}C$) to investigate the feasibility of detecting its fermentation degree by measuring gas composition inside the packages. The gas composition inside the kimchi package continuously changed due to $CO_2$ evolution during fermentation. Regardless of temperature, the fermentative gas accumulation in the package caused $CO_2$ concentration to increase by two-stepwise pattern, but $O_2$ concentration to decrease exponentially. As $CO_2$ concentration increased secondarily, the pH values of kimchi decreased proportionally (r>0.968). The production of $CO_2$ during kimchi fermentation was stimulated at higher temperatures and affected by seasonal factor. Kimchi made from winter baechu produced more fermentative gas than that from summer baechu. It was suggested that the changes in $CO_2$ concentration could be used as a characteristic index for indicating the fermentation course of packaged kimchi products.

• The Journal of Korean Medicine
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• v.23 no.1
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• pp.24-36
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• 2002

Objectives: The chemotherapeutic potential of Gagamgilgyung-tang for the treatment of human lung cancer, the antitumorigenic effects of Gagamgilgyung-tang on the proliferation and apoptosis of human lung cancer cell line A427 were investigated using molecular biological approaches, Methods: To determine Gagamgilgyung-tang concentrations which do not evoke cytotoxic damage to the cell line, cell viability was examined by MTT assay. To prove Gagamgilgyung-tang's antitumorigenic potential to human lung cancer, [3H]thymidine incorporation assay, trypan blue exclusion and Cpp32 protease activity assays and quantitative RT-PCR analysis were examined. Results: While A427 cells treated with $0.1-2.0{\mu\textrm{g}}/ml$ of Gagamgilgyung-tang showed no recognizable effect, marked reductions of cell viability were detected at concentrations over $5.0{\;}\mu\textrm{g}/ml$. DNA replication of A427 cells was inhibited by Gagamgilgyung-tang in a dose-dependent manner and Gagamgilgyung-tang induced the G1 cell cycle arrest through inhibition of DNA replication. Gagamgilgyung-tang triggered apoptotic cell death of A427 and enhanced the apoptotic sensitivity of the cells that were injured by a DNA damage-inducing chemotherapeutic drug etoposide. Gagamgilgyung-tang induces expression of growth-inhibiting genes such as p53 and p21/Wafl whereas it inhibited expression of growth-promoting genes such as c-Myc and Cyclin D1. Expression of a representative apoptosis-inducing gene Bax was also found to be induced by Gagamgilgyung-tang while apoptosis-suppressing Bcl-2 expression was not changed. Conclusions: Gagamgilgyung-tang could suppress the abnormal growth of tumor cells by suppressing the survival of genetically altered cells via induction of apoptosis. This study suggests that Gagamgilgyung-tang might have an antitumorigenic potential to human lung cancer cells, which might be associated with its growth-inhibiting and apoptosis-inducing properties.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.305-311
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• 2006

Purpose : GnRH analogues(GnRHa) are used to treat central precocious puberty(CPP). However, in some patients, the GV decrease is so remarkable that it impairs predicted adult height(PAH); and there fore, the addition of growth hormone(GH) is suggested. We analysed the growth changes during two years and final adult height(FAH) in girls with idiopathic CPP treated with combined therapy, compared with those of girls treated with GnRHa alone. Methods : For the analysis, we classified the patients, who was treated for longer than two years, into three groups depending on the initial PAH and combination of GH; PAH_L, treated with GnRHa and PAH less than midparental height(MPH) - 5 cm. PAH_H, treated with GnRHa and PAH greater than MPH - 5 cm. GnRHa＋GH, combined GH treatment, regardless of PAH before treatment. We analysed the GV and PAH change during the first two years and FAH. Results : In PAH_L, the PAH(SDS) at first year of therapy was significantly increased to $153.5{\pm}6.5cm(-1.4{\pm}1.3)$ from $149.7{\pm}6.4cm(-2.1{\pm}1.3)$ before treatment(P=0.004). In PAH_H, there was no significant increase in PAH during the two years of treatment. During the first year of combination of GH and GnRHa, GV and PAH increased significantly. We observed significant increases in FAH, comparing to the initial PAH in the PAH_L and GnRHa＋GH groups. The height gains(FAH - initial PAH) were significantly higher in the PAH_L and GnRHa＋GH groups than that in the PAH_H group. Conclusion : This study suggests the FAH and height gains are improved in patients, whose predicted adult height before treatment was shorter than those with higher predicted adult height, with the treatment of GnRHa alone or in combination with GH. GH could not improve the final adult height, but compensated the growth in patients whose growth velocity was decelerated by GnRHa alone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.41-51
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• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.890-895
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• 2021

This study investigated the quality characteristics and antioxidant activity of bread containing Codium fragile powder (CFP; 1, 3, 5%). As the CFP content increased, the fermentation expansion (%) of the dough significantly decreased (P<0.05). No significant difference (P>0.05) was observed in the moisture content (%) of bread as the CFP content increased, but the pH and weight significantly increased (P<0.05). The bread volume, specific volume, and baking loss significantly decreased (P<0.05) as the CFP content increased. The L, a and b Hunter colors on the bread crust showed a tendency to decrease (P<0.05) as the CFP content increased. Compared with the control, the bread crumb darkened and presented a green color as the CFP content increased. Compared with the control (DPPH, 4.10%, ABTS, 2.17%), the free radical scavenging activities of DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid] as antioxidant indices gradually increased (P>0.05) with the CFP content increased (DPPH, 9.77-18.63%, ABTS, 4.30-11.40%). Collectively, these results can make a compelling case for the functional development of CPP-containing bread due to its antioxidant properties. Furthermore, this study intends to contribute to the development of various processed seaweed foods by expanding the availability of CFP, which is easy to use and store for a long time.