• 한국환경과학회지
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• 제21권10호
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• pp.1265-1274
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• 2012

This study was conducted to investigate the extraction characteristics including total polyphenol compound content (TPC) and the antioxidative effect of Rumex crispus root extract on commercial corn oil. Extraction yield was increased with extraction temperature but decreased with extraction ratio. No significant differences in aromatics content were found among the extracts prepared with various extraction conditions; extraction ratio, extraction temperature, extraction pH and composition of extractant. Total flavonoid content of the extract was increased with extraction temperature and extraction pH, and highest value of it was found when extractant composition of ethanol in water was 75%. Total polyphenol compound content (TPC) of the extract with 10 fold extraction ratio showed the highest value, but no significant difference in TPC was found with extraction temperature. Reducing power and DPPH (${\alpha}$,${\alpha}$-diphenyl-${\beta}$-picrylhydrazyl) radical scavenging ability (RSA) of the extract in spectrophotometric absorbance were decreased with extraction ratio but increased with extraction temperature and showed 63.1%~98.4% and 67.6%~86.7% of those of ascorbic acid in reducing power and DPPH RSA, respectively. The antioxidative effects of the extract on corn oil were 84.8~93.0% of that of commercial butylated hydroxytoluene, the antioxidant index value was highest when the ethanol composition to water in extractant was equal ratio.

• 한국잠사곤충학회지
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• 제44권2호
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• pp.93-98
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• 2002

천연쪽 색소를 사용하는 의한 견직물의 염색 방법을 확립하고자 시험결과 환원제인 Sodium Hydrosulfite를 사용한 경우 염색온도가 3$0^{\circ}C$에서는 30분, 5$0^{\circ}C$에서는 10분 염색 한 것이 표면 염착농도(K/S)가 가장 높았고, 염색액의 pH 7.4 정도인 환원제 및 염료량을 4 g/l일 경우에 가장 높았다. 1회 염색직물의 표면염착농도(K/S)는 개선은 7.20, 기존염색 방법은 1.09이었으며, 염색 직물의 분리한 색소와 염료색소는 모두 청색색소와 적색색소의 2개의 성분이었고 분자량은 262이었으며, 기존과 개선 모두 정균율은 99.8%이상으로 항균성 이 우수하였다.

• 한국축산식품학회지
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• 제43권3호
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• pp.471-490
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• 2023

In this study, the duck eggs were salted with none or 2.5% and 5.0% (v/v) of liquid smoke (LS), respectively. As a control, samples salted without LS were used. The 2-thiobarbituric acid (TBA) values, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and reducing power of the three groups were tested at 0, 7, 14, and 21 and 28 days to determine the effects of LS on the antioxidant activity of treated eggs. In addition, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-Nose) were used to analyze the volatile flavor components of fresh duck eggs, LS, control, and salted duck eggs enriched with 2.5% (v/v) LS after 28 days of salting. The TBA value considerably increased with an increase in salting period, and the treated egg's TBA value significantly associated with LS concentration. The TBA value decreased as the LS concentration increased. The amount of LS present was highly associated with their capacity to scavenge DPPH radicals. The reducing power of the samples was substantially correlated with the LS concentration, and the reducing power increased with increasing LS concentration. The GC-MS data revealed that phenols and ketones were the predominant chemicals present in the LS, and they were also found in the eggs added to the LS even though they were absent in the fresh eggs and control. The flavor of the control group and treated eggs with LS differed significantly, according to the principal component analysis and radar map of the E-nose. The texture study results revealed that the LS significantly impacted the hardness, cohesiveness, and chewiness of eggs.

• 산업경영시스템학회지
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• 제45권2호
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• pp.56-64
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• 2022

Many studies have suggested that e-commerce value creation potential depends on four interdependent factors Lock-In, Complementarity, Efficiency, and Novelty. In order to survive in the recent fierce competition, companies have also secured e-Trust that strengthens long-term business relationships by reducing consumer uncertainty. This study, while analyzing the value creation factors (Lock-in, Complementarity, Efficiency, Novelty, e-Trust) of recent e-commerce (online shopping mall) companies from the point of view of purchase intention, customer value (Functional value, Emotional value, Social value) We present an academic proposition that can also examine the mediating effect of value). First, through previous studies on value-based strategy and value creation in e-commerce, various discussions on the theoretical background necessary for effective value-based strategy establishment and strategy execution of e-commerce (online shopping mall) companies were reviewed. Second, it provides academic discussion and practical implications by presenting academic propositions on the value creation factors of e-commerce (online shopping mall) companies, purchase intentions, and customer value, and confirming the basis through empirical analysis.

• 한국식품영양학회지
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• 제24권4호
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• pp.761-769
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• 2011

The objective of this study was to investigate the physicochemical properties of Korean traditional soy sauces made with soybeans sown in different producing regions(Hadong, Paju) and in different seeding periods(late-May, mid-June, late-June). The total acidity, salt content, chromaticity, browning, amino nitrogen content and the reducing sugar content of the soy sauce samples were compared. It was found that the total acidity level and the amino nitrogen contents were significantly lower in the soy sauce made with mid-June soybeans, and that these properties increased as the sauce aged. Salt content increased with the aging period regardless of the region of production. The reducing sugar content of Paju soy sauce was the highest in late -June, and for the Hadong region, highest in late-May. The sauce made with Hadong soy beans showed an increase in reducing sugar content positively correlated with the aging period. Reducing sugar content in the samples of Paju soy sauce decreased up to 60 days of aging, but increased after this point. In Paju soy sauce, the brightness(L value) was significantly higher in mid-June, and the Hadong variant it was higher in late -May. The yellowness(b value) at the beginning of the aging process was high in late -June for Hadong soy sauce, but overall it was higher in the mid-June period. The more matured soy sauce samples were darker and showed both higher a and b values. The browning was the lowest in the mid -June regardless of the regions and it increased with the aging period regardless of the production regions. The salt, amino nitrogen contents, browning and yellowness showed significant correlations among the samples. In conclusion, the seeding period of soy beans may affect the characteristics of produced soy sauce alongside the aging conditions.

• 한국식품과학회지
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• 제16권1호
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• pp.41-46
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• 1984

Aspergillus niger sherumanni IAM 2059가 분비하는 펙틴질분해효소 중에서 endo-polygalacturonase 를 Sephadex G-100, DEAE-Sephadex A-50을 이용하여 분리하고 점도감소와 분해산물분석을 통해 효소의 특성을 조사하였다. Chromatography를 통해 얻은 3 개의 역가 fraction (F-A, F-I 및 F-II) 은 각각 exo형 효소, eodo-polygalacturonase, endo-polymethylgalacturonase 이었다. endo-polygalacturonase의 역가 최적 pH는 환원당 생성으로는 pH4.2 근방이었고 점도감도로는 pH4.7 근방이었다. 이 효소의 Z-value는 $7.5^{\circ}C$이고 $D40^{\circ}C$는 240sec 이며 $40^{\circ}C$에서 활성화엔트로피(Enthalphy of activation) 217.3KJ/mol, 활성화엔트로피(Entropy of activation) 409.2J/mol.K, 활성화자유에너지(Free energy activation) 89.2KJ/mol 이었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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• pp.229-233
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• 1995

In this study we have the properties of drying shrinkage crack of hardened cement mortar using admixtures. The drying shrinkage cracking test process has been examined by the restrained drying shrinkage strain by restraining rate measuring properties of strain-with- restraint by JIS original proposal and keeps a flow value of mortar about 100$\pm$5%. The results show that the usage of shrinkage reducing agent 1.5% was effective on the control of drying shrinkage in OPC and CP by restraining rate 20% and strain-with-restraing 20~30 $\mu$, the usage of expansion agent 0.45% was effective by restraining rate 50~60% and strain-with-restraint 40~80$\mu$, and the effectiveness was increased with shrinkage reducing agent. Also. admixtures such as Flyash, CP and NC reduced restrained shrinkage and drying shrinkage cracking and more with shrinkage reducing agent

• 한국연초학회지
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• 제5권1호
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• pp.25-33
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• 1983

This study was carried out to investigate the transplanting time, optimum fertilization and harvesting method, chemical contents and physical properties of burley tobacco in paddy field. The results obtained as follows. 1. It is recommendable to transplant after March. 29 to escape the frost injury. By reducing compound fertilizer and whole plant stalk curing, advanced the. last priming date by 5-8 days. 2. Total alkaloid, total nitrogen and phosphorus contents of cured leaf was comparable to those of upland-produce(1 tobacco, but potassium and chloride contents some what high. 3. Filling power and combustibility was also comparable to upland, and filling power was increased by reducing fertilizer and whole plant stalk curing. 4. In the 20o reducing fertilizer-5 Primings volt. the yield was some what decreased, but visual quality and value per 10a were high. 5. The total raw income of tobacco and rice cropping was increased 124~170% than that of rice cropping.

• 동력기계공학회지
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• 제1권1호
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• pp.35-41
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• 1997

Annular jet pump can be used for the transportation of solid materials and fish. The effect of mixing chamber on the characteristics of annular jet pump is sought in this paper. Experiments were done for several reducing angles of mixing chamber, and for several throat area. Water was used for both the primary fluid and secondary fluid. A vortex was observed for the straight mixing chamber, but it was not observed for the mixing chamber whose reducing angle is $18^{\circ}$ or higher. The efficiency curves for the annular jet pump are presented in this paper, showing the annular jet pump which has 240 reducing angle and $0.611{\sim}0.73$ value of At/As. is most effective among the tested several annular jet pumps.

• 대한인간공학회지
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• 제26권2호
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• pp.157-165
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• 2007

The Work-Related Musculoskeletal Disorders (WMSDs) can be occurred by various factors such as repetition, forceful exertions and awkward postures. Especially, occurrences of the WMSDs on the waist and lower limb are reported in workplaces, demanded standing postures for a long time, in service and manufacturing industry. The static and standing postures without movement for a long time increase work loads to the lower limb and the waist. Accordingly, anti-fatigue mat or anti-fatigue insole is used as a preventing device of the WMSDs. However anti-fatigue mats are limited in space and movement. In this study, multi-elastic insoles are designed and shown the effects of the workload reduction for a long time under the standing work. The foot pressures and EMG (Electromyography) are measured at 0 hour and after 2 hours by 6 health students in their twenties. The 6 prototype insoles are designed with three elastic (Low, Medium and High). These insoles are compared with no insole (insole type 7) as control group. The EMG measurement was conducted to waist (erector spinae muscle), thigh (vastus lateralis muscle) and calf (gastrocnemius muscle). The foot pressure is analyzed by mean pressure value and the EMG analysis is investigated through MF (Median Frequency), MPF (Mean Power Frequency) and ZCR (Zero Crossing Rate). The results of the foot pressure show that the multi-elastic insoles had smaller foot pressure value than that of no-insole. Moreover, Insole 2 and Insole 3 have the smallest increasing rate in foot pressure. The EMG results show that the multi-elastic insoles had smaller EMG shift value than that of no-insole in 2 hour, and then shift value shows the smallest value in Insole 2. Therefore, this study presents that the multi-elastic insoles have reducing effects of the work load for a long time standing work in both side of foot pressure and EMG.