• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.701-711
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• 2020

Purpose: In this study, the risk of flammability of a liquid mixture was experimentally confirmed because the purpose of this study was to confirm the increase or decrease of the flammability risk in a mixture of two substances (combustible+combustible) and to present the risk of the mixture. Method: Flash point test method and result processing were tested based on KS M 2010-2008, a tag sealing test method used as a flash point test method for crude oil and petroleum products. The manufacturer of the equipment used in this experiment was Japan's TANAKA. The flash point was measured with a test equipment that satisfies the test standards of KS M 2010 with equipment produced by the company, and LP gas was used as the ignition source and water as the cooling water. In addition, when measuring the flash point, the temperature of the cooling water was tested using cooling water of about 2℃. Results: First of all, in the case of flammable + combustible mixtures, there was little change in flash point if the flash point difference between the two substances was not large, and if the flash point difference between the two substances was low, the flash point tended to increase as the number of substances with high flash point increased. However, in the case of toluene and methanol, the flash point of the mixture was lower than that of the material with a lower flash point. Also, in the case of a paint thinner, it was not easy to predict the flash point of the material because it was composed of a mixture, but as a result of experimental measurement, it was measured between -24℃ and 7℃. Conclusion: The results of this study are to determine the risk of mixtures through experimental studies on flammable mixtures for the purpose of securing the effectiveness of the details of the criteria for determining dangerous goods in the existing dangerous goods safety management method and securing the reliability and reproducibility of the determination of dangerous goods Criteria have been presented, and reference data on experimental criteria for flammable liquids that are regulated in firefighting sites can be provided. In addition, if this study accumulates know-how on differences in test methods, it is expected that it can be used as a basis for research on risk assessment of dangerous goods and as a basis for research on dangerous goods determination.

• Applied Chemistry for Engineering
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• v.22 no.2
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• pp.178-184
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• 2011

In this study, the antibacterial, antioxidative and inhibitory effects of Allium cepa peel extracts on tyrosinase and elastase were investigated. MIC values of the ethyl acetate fraction of Allium cepa peel on especially, S. aureus among the skin resident flora (Staphylococcus aureus, S. aureus; Propionibacterium acnes, P. acnes; Pityrosporum ovale, P. ovale; Escherichia coli, E. coli) were 0.06%. The aglycone fraction showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity ($FSC_{50}=5.05{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of the ethyl acetate fraction and aglycone fraction in the luminol-dependent $Fe^{3+}-EDTA/H_2O_2$ system were 0.05 and $0.03{\mu}g/mL$, respectively. The cellular protective effect of the aglycone fraction on the rose-bengal sensitized photohemolysis of human erythrocytes exhibited more prominent (${\tau}_{50}$, 480 min at $25{\mu}g/mL$). The inhibitory effects ($IC_{50}$) of the ethyl acetate fraction and aglycone fraction on tyrosinase were 9.16 and $8.68{\mu}g/mL$, the inhibitory effect ($IC_{50}$) of the aglycone fraction on elastase was $14.12{\mu}g/mL$ The transepidermal water loss of the cream containing 0.1% ethyl acetate fraction was decreased from $8.3g/m^2h$ in control to $6.8g/m^2h$ in the subjects applied with cream containing the ethyl acetate fraction. These results indicate that extract/fractions of Allium cepa peel can function as antioxidant in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS, and possibly as antiaging agents. Allium cepa peel extract could be used as a new cosmeceutical for whitening and anti-wrinkle products.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.591-597
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• 2011

Forest carbon stock changes in a national forest were assessed by CBM-CFS3 model with different management scenarios to support decision making for a long term forest planning. Management scenarios were composed with 4 different levels of timber harvesting - current harvesting level (scenario1), 30% increment in each period (scenario2), 3 times increment (scenario3), and 5 times increment (scenario4). For each scenarios, changes in total carbon stocks, carbon stocks of each carbon pools, carbon stocks of harvested wood products (HWP) and age class structure were estimated over 100-year planning horizon. The estimated total carbon stock including HWP at the end of final period (100 years) was 433.1 tC/ha under scenario 1, but the age class structure has skewed right to the upper classes, which is not desirable for sustainable forest management. Under the scenario 4, however, the total carbon stock decrease to 385.5 tC/ha and the area of old growth forest show a significant decline. The estimated total carbon stock under scenario 2 and 3 were 411.7 tC/ha and 410.5 tC/ha respectively, and it was able to maintain the initial level of the forest carbon stocks during the planning horizon. Also the age class structures under the scenario 2 and 3 were evenly distributed from class 1 to class 8. Overall, scenario 2 and 3 were the most acceptable forest management options, in terms of carbon stock changes and age class structure.

• Food Science and Industry
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• v.53 no.1
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• pp.2-32
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• 2020

In recent years, significant importance has been given to chitooligosaccharides (COS) due to its potent notable biological applications. COS can be derived from chitosan which is commonly produced by partially hydrolyzed products from crustacean shells. In order to produce COS, there are several approaches including chemical and enzymatic methods which are the two most common choices. In this regard, several new methods were intended to be promoted which use the enzymatic hydrolysis with a lower cost and desired properties. Hence, the dual reactor system has gained more attention than other newly developed technologies. Enzymatic hydrolysis derived COS possesses important biological activities such as anticancer, antioxidant, anti-hypersentive, anti-dementia (Altzheimer's disease), anti-diabeties, anti-allergy, anti-inflammatory, etc. Results strongly suggest that properties of COS can be potential materials for nutraceutical, pharmaceutical, and cosmeceutical product development.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.12-18
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• 2021

The in vitro antioxidant activity of oregano seed fractions, fractionizing with 80% ethanol, n-hexane, ethyl acetate, n-butanol, and water, was evaluated, and their effects on edible oils were determined in corn oil at 180℃. The ethyl acetate fraction had the highest radical-scavenging activity. The ferric reducing antioxidant power activity and total phenol content of the ethyl acetate fraction were determined as 6,130 µmol ascorbic acid equivalents/g extract and 770 µmol tannic acid equivalents/g extract, respectively, which were significantly higher than those of the other fractions (p<0.05). Primary and secondary oxidation products in corn oil added with the ethyl acetate fraction of oregano seed significantly decreased by 1.5 and 1.26 times, respectively, compared with those in the control groups. The major volatile ingredients in the ethyl acetate fraction of oregano seeds were determined to be carvacrol, thymoquinone, and 3-cyclopentylcyl-cyclopentan-1-one. Ethyl acetate is a suitable solvent for extracting antioxidant compounds from oregano seeds and can be used as a natural antioxidant.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.1
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• pp.8-15
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• 2021

TiO2 has been used in various fields such as solar cells, dental implants, and photocatalysis, because it has high physical and chemical stability and is harmless to the body. TiO2 nanofibers which have a large specific surface area also show a good reactivity in bio-friendly products and excellent photocatalysis in air and water purification. To fabricate TiO2 nanofibers, an electrospinning method was used. To observe the diameter of TiO2 nanofibers with fabrication variables, the fabrication variables was divided into precursor composition variables and process variables and microstructure was analyzed. The concentrations of PVP (Polyvinylpyrrolidone) and TTIP (Titanium(IV) isopropoxide) were selected as precursor composition variables, and inflow velocity and voltage were also selected as process variables. Microstructure and crystal structure of TiO2 nanofibers were analyzed using FE-SEM (Field emission scanning electron microscope) and XRD (X-ray diffraction), respectively. As-spun TiO2 nanofibers with an average diameter of about 0.27 ㎛ to 1.31 ㎛ were transformed to anatase TiO2 nanofibers with an average diameter of about 0.22 ㎛ to 0.78 ㎛ after heat treatment of 3 hours at 450℃. Anatase TiO2 nanofibers with an average diameter of 0.22 ㎛ can be expected to improve the photocatalytic properties by increasing the specific surface area. To change the average diameter of TiO2 nanofibers, the control of precursor composition variables such as concentrations of PVP and TTIP is more efficient than the control of electrospinning process variables such as inflow velocity and voltage.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.334-342
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• 2022

To meet the needs of Muslim consumers, sausages were prepared using Halal-certified chicken thighs and different amounts of biji powder (0, 20, 30, 40, and 50%), and then the properties of the sausages were compared. As the biji powder levels increased, both the moisture content and the pH of the sausages significantly decreased, whereas their fiber content increased. As the biji powder levels increased, the free radical scavenging effect (DPPH, ABTS) and water holding capacity also increased, and the textural properties also improved. When Muslim consumers evaluated the sensory attributes of the sausages prepared in this experiment and those currently on the market, the ones prepared in this experiment were preferred over the market products. Based on the above results, chicken sausage for Muslim consumers could be successfully produced, and their overall quality and antioxidant effects could be improved by the addition of biji powder (up to 30%).

• Journal of Life Science
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• v.32 no.1
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• pp.1-10
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• 2022

Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.

• Journal of Korea Port Economic Association
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• v.38 no.1
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• pp.1-14
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• 2022

The change in the management environment of the logistics industry in the era of global competition is becoming an era in which customers choose companies. Differentiation from competitors through the provision of products and services suitable for customers As customers' choices change depending on their superiority, companies are constantly striving to receive or retain customers' choices. Ultimately, this competitive structure can be seen as the importance of long-term relationship building. Therefore, in this study, we examined how factors related to transaction characteristics performed by logistics companies for customer satisfaction in the transaction relationship between cargo companies and shippers affect performance and long-term transaction intentions. First, we derived the factors of logistics service, cost, logistics infrastructure, and company competency, which are transaction characteristics factors of a logistics company that must be specifically realized for customer satisfaction in transactions between logistics companies. Second, we analyzed how the transaction characteristics factors of a logistics company affect the company's performance, and finally, how the company's performance factors affect long-term transaction intentions. As a result of empirical analysis, there were no statistically significant results on the relationship between transaction characteristics and performance of logistics companies, which can be attributed to the small size of the logistics companies that were the sample. In other words, logistics companies that do not have sufficient capacity to provide services at low prices have no choice but to engage in constant bleeding competition. It can be seen that it reflects the characteristics of the industry. On the other hand, the relationship between corporate performance factors and long-term transaction intention was found to have a positive relationship. The higher the level of partnership with logistics companies and visible financial performance is, the higher the transaction will be in the future, and the more the transaction volume will be gradually increased. And even if it costs a little more, it can be seen that the intention to continue trading is greatly expressed.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.181-186
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• 2021

In this study, the physical characteristics, antioxidant activity, and stability of muffins prepared with acai berry concentrate-loaded nanocapsules were evaluated. The size of the acai berry nanocapsules significantly increased with higher chitosan and lower Arabic gum concentrations. Based on the total phenolic content and antioxidant activity, the free acai berry concentrate showed significantly stronger antioxidant activity than that of the acai berry concentrate-loaded nanocapsules using chitosan and Arabic gum because of the entrapment of encapsulated acai berry. The physicochemical and textural properties of the muffin prepared with acai berry concentrate-loaded nanocapsules did not show notable differences compared with the control muffin. However, the stability of acai berry concentrate in terms of total phenolic content and antioxidant activity was effectively enhanced by nanoencapsulation while baking the muffin. This study suggested that acai berry concentrate-loaded nanocapsules are potential ingredients for bakery products.