• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.430-439
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• 2021

Essential oils with excellent antibacterial activity were used to study the inhibitory effect against the six types of food poisoning biofilms formed on the surfaces of polyethylene (PE) and stainless steel (SS) that are widely used for food processing instruments and containers. The antibacterial activity of 20 kinds of essential oils was tested using the disk diffusion method. The result showed the degree of antibacterial activity in the following order: cinnamon> clove> lemongrass> peppermint> pine needle (highest to lowest). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of cinnamon and clove oil were in the range of 0.63-1.25 mg/mL and 1.25-2.50 mg/mL, respectively. The MIC and MBC of lemongrass oil were 1.25-2.50 mg/mL and 2.50-5.00 mg/mL, respectively, showing slightly less antibacterial activity. Although the preventive effect of three types of essential oils on the biofilm formation differed slightly depending on food poisoning bacteria, PE, and SS, it was found that the precoating of 0.5% cinnamon, clove, and lemongrass oil on the PE and SS affects the formation of biofilm. Increased essential oil concentration significantly inhibited the biofilm formation for all food poisoning bacteria (P<0.05), and biofilms of Listeria monocytogenes and Staphylococcus aureus were not formed when treated with 0.5% cinnamon and clove oil. The elimination effect of food poisoning bacteria biofilms formed on the surfaces of PE and SS differed depending on the type of food poisoning bacteria. Still, the biofilm elimination effect increased as the essential oil concentration increased, and the biofilm elimination rate of clove oil was generally high. Therefore, this study found that the cinnamon and clove essential oils (0.5%) are suitable natural materials that effectively prevent, inhibit, and remove the biofilms formed by the food poisoning bacteria on the surfaces of polyethylene and stainless steel.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.218-224
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• 2019

This study was conducted to compare the effect of salicylic acid (SA), an ethylene biosynthesis inhibitor, and the 1-methylcyclopropene (1-MCP) fumigation, to prevent fruit quality deterioration and physiological disorders during the shelf-life of Korea's leading export grape variety 'Campbell Early'. The berries treated with SA after 1-MCP fumigation (1-MCP+SA) showed a higher firmness value and titratable acidity than single treatment of SA or 1-MCP. The rate of shattered berry was high as 41.7% for 100ppm ethephon spray, 40.8% for $25{\mu}M$ SA, and 38.2% for 1,000ppb 1-MCP, but showing only 18.7% when the SA was applied after 1-MCP fumigation. The ratio of short brushes less than 1mm was largest at 74.3% for ethephon treatment, while 1-MCP+SA treatment was found to have the longest brush length among all treatments, with a 2-4mm ratio of 22.8% and a 4-6mm ratio of 27.9%. The weight of rachis was found to be the lowest at 2.3g in the ethephon treatment, and the reduction of rachis weight loss per cluster by 1-MCP+SA treatment was evident. In addition, 1-MCP+SA treatment were effective in mitigating stem browning and berry decay during the 16-day storage period at $19^{\circ}C$ in this cultivar, so it is believed that they can be used as a practical post-harvest treatment in grape exportation.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.2
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• pp.72-80
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• 2019

Purpose: The purpose of this study is to compare and analyze the shear bond strength and fracture pattern in different enamel tooth surface treatments for resin splinting materials. Materials and Methods: G-FIX and LightFix were used as tooth splinting materials. Twenty bovine mandibular incisors were used for the preparation of the specimens. The exposed enamel surface was separated into four parts. Each tooth was treated with 37% phosphoric acid, 37% phosphoric acid + adhesive resin, 37% phosphoric acid + G-premio bond, and G-premio bond for each fraction. Shear bond strength was measured using a universal testing machine. After measuring the shear bond strength, the fractured surface of the specimen was magnified with a microscope to observe the fracture pattern. Two-way ANOVA was used to verify the interaction between the material and the surface treatment method. One-way ANOVA was used for comparison between the surface treatment methods of each material and post-hoc test was conducted with Scheffe's test. An independent t-test was conducted to compare shear bond strengths between materials in each surface treatment method. All statistics were conducted at 95% significance level. Results: G-FIX, a tooth splinting resin, showed similar shear bonding strength when additional adhesive resins were used when material was applied after only acid etching, and LightFix showed the highest shear bonding strength when additional adhesive resins were used after the acid etching. In addition, both G-FIX and LightFix showed the lowest shear bond strength when only self-etching adhesive was applied without additional acid etching. Verification of interactions observed interconnection between resins and surface treatment methods. Most of the mixed failure was observed in all counties. Conclusion: When using G-FIX and LightFix, which are tooth-splinting materials, it is considered that sufficient adhesion will be achieved even after applying only acid etching as instructed by the manufacturer.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.34-42
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• 2019

Baseflow which is one of the unmeasurable components of streamflow and slowly flows through underground is important for water resource management. Despite various separation methods from researches preceded, it is difficult to find a significant separation method for baseflow separation. This study applied the MRC method and developed the improved approach to separate baseflow from total streamflow hydrograph. Previous researchers utilized the whole streamflow data of study period at once to derive synthetic MRCs causing unreliable results. This study has been proceeded with total nine areas with gauging stations. Each three areas are selected from 3 domestic major watersheds. Tool for drawing MRC had been used to draw MRCs of each area. First, synthetic MRC for whole period and two other MRCs were drawn following two different criteria. Two criteria were set by different conditions, one is flow condition and the other is seasonality. The whole streamflow was classified according to seasonality and flow conditions, and MRCs had been drawn with a specialized program. The MRCs for flow conditions had low R2 and similar trend to recession segments. On the other hand, the seasonal MRCs were eligible for the baseflow separation that properly reflects the seasonal variability of baseflow. Comparing two methods of assuming MRC for baseflow separation, seasonal MRC was more effective for relieving overestimating tendency of synthetic MRC. Flow condition MRCs had a large distribution of the flow and this means accurate MRC could not be found. Baseflow separation using seasonal MRC is showing more reliability than the other one, however if certain technique added up to the flow condition MRC method to stabilize distribution of the streamflow, the flow conditions method could secure reliability as much as seasonal MRC method.

• (The) Korean Journal of Advertising
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• v.27 no.3
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• pp.7-25
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• 2016

According to recent studies, the location of visual information has a significant impact on consumers' interpretation and judgment in various contexts. In particular, vertical positioning is relevant to the perception of weight: consumers tend to interpret that products are heavier when information is placed at the bottom of a page or section rather than the top. This is due to the common perception that heavy things would sink to the bottom and light things would float up. Consistent with this research stream, the current study investigates how the vertical location of freebie information influences promotion evaluation. We hypothesize that consumers assume that the complimentary product is heavier when the information about it is displayed at the bottom compared to when the information is displayed at the top. Two experiments were conducted. In experiment 1, we show how the location of "get one free" information impacts the evaluation of the sales promotion in a "Buy two and get one free" context. When the complimentary information was displayed below rather than above the main product information, consumers evaluated the sales promotion more favorably. Experiment 2 tests the generalizability of the vertical location effect by using a different type of information and product: a visual picture of vitamin tablets rather than the numeric information as in Experiment 1. The dependent variable was also extended to the perceived amount of the promoted product. We suggest the boundary condition that the proposed effect is moderated by the presence or absence of an explicit message about the amount. Without an explicit message about the amount of the product, the results were similar to those of experiment 1 in that consumers perceived that the product offered a greater amount when the complimentary information was displayed at the bottom rather than at the top. However, the location effect disappeared with an explicit message about the amount. This confirms the moderating effect that presenting an explicit message about the amount is a crucial boundary condition for location effect in a value added promotion. Marketers can use this knowledge to formulate strategies in a variety of sales promotion conditions.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.267-275
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• 2018

The purposes of this study were to analyze the mineralogical characteristics of slaked lime used for wall repair of traditional buildings in Bagan, Myanmar and to evaluate the physical properties of lime plaster produced by the same method as Bagan region. In the X-ray diffraction and thermal analysis of the Myanmar slaked lime, portlandite ($Ca(OH)_2$) and brucite ($Mg(OH)_2$) were detected as main constituent minerals, and a carbonate rock mainly composed of dolomite ($CaMg(CO_3)_2$) minerals may be used as a raw material to make slaked lime. The field-emission scanning electron microscope analysis showed that the Myanmar slaked lime was composed of irregularly shaped crystals of $0.5{\mu}m$ or larger and a small amount of $0.1{\mu}m$ of plate - like crystals. The size and uniformity of crystals in Myanmar lime is different from that of Korea slaked lime. This may be attributed to the effect of the mineral composition and the lime hydration method of Myanmar, which produces slurry by immersing the burnt lime in excess water for a long period of time. The compressive strength of the lime plaster in Myanmar resulted in a mean value of $1.13N/mm^2$ for the specimens cured for 28 days. The strength of the specimens with Bale juice was $1.03N/mm^2$, respectively. The lime is an air setting material that exhibits strength through long carbonation process. Therefore, it is necessary to evaluate physical properties according to curing period through long-term curing over 28 days in the future.

• Journal of Society of Occupational Therapy for the Aged and Dementia
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• v.12 no.2
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• pp.87-95
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• 2018

Objective : Vibration stimulators are easier to obtain in clinical settings than other treatment tools, and it is advantageous that the arm activation training can be performed passively. Despite the following advantages, recent studies on vibration sense have not been activated yet. The purpose of this study was to investigate the effect of vibration sensation on the hands of the affected upper limb on unilateral reduction of stroke patients. Method : Patients with unilateral neglect due to stroke were enrolled in this study for about 3 weeks from October 19, 2018 to November 7, The research design used ABA design among the single-subject experimental research design, and a total of 18 circuits (4 baseline, 6 intervention, 3 baseline regression) were performed once a day on weekdays Respectively. MMES-K was used to select the subjects. Line bisection test (LBT), Albert's test and Star Cancellation Test (SCT) were used as unilateral neglect test. For the analysis, the baseline and intervention period measurements were visually analyzed using graphs and mean values were used. Result : All three evaluations showed that the number of errors missed during the training period was lower than the baseline period, and this decrease remained after training. The error was reduced by an average of $2{\pm}1.2$ omissions and an average omissions of $0.6{\pm}0.5$ omitting an average of $4.5{\pm}1$ omissions in the line break test. As a result of the Albert test, the average error decreased by $22.5{\pm}1.9$ omissions and $8{\pm}7.3$ omissions and $0.3{\pm}0.5$ omissions, respectively. In the star clearance test, the average error decreased from $26{\pm}4.6$ to $21.8{\pm}1.7$ and $20{\pm}0$, respectively. Conclusion : In this study, vibrotactile stimulation therapy showed a continuous effect on improving unilateral neglect. Based on these findings, further research should be conducted in order to improve objectivity in future studies. Further research on various arbitration methods that maximize the effect of intervention will be needed.

• Journal of The Korean Association For Science Education
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• v.38 no.6
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• pp.765-780
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• 2018

The purpose of this study is to synthesize the theoretical perspectives, research methods, and research results of teachers' professional vision by reviewing and analyzing previous research papers and to suggest implications for science teacher education and research. Three databases were used to search peer reviewed journal articles published between 1997-2017, which include 'teachers' and 'professional vision' explicitly in abstracts and empirical studies only. 21 articles in total were analyzed and review results are as follows. First, researchers regarded professional vision as a new concept of teacher professionalism. Previous research viewed professional vision as integrated structure of teachers' knowledge or ability activated at specific moment. Second, the analytical framework of professional vision included two aspects; 'selective attention' and 'reasoning'. Several aspects of lessons or the desirable teaching and learning factors are suggested as the subcategories of selective attention. Hierarchical levels or independent reasoning ability factors are suggested as the subcategories of reasoning process. Third, research on teachers' professional vision focused more on middle school teachers than elementary teachers and on various subject areas. Most studies used video clips and more cases of using videos of non-participants were found. In case of measurement of professional vision, most quantitative scoring methods were whether the responses of experts and teachers on video clips were consistent. Last, most studies examined or assessed teachers' professional vision. It is reported that in-service teachers' professional vision was evaluated higher than novice teachers' and using video clips were effective to examine and improve teachers' professional vision.

• Clean Technology
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• v.25 no.3
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• pp.245-255
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• 2019

Pressurized oxy-fuel combustion is a promising technology for $CO_2$ capture with a benefit of improving power plant efficiency compared with atmospheric oxy-fuel combustion. Prior to $CO_2$ compression in this process, a flue gas condenser (FGC) is used to remove $H_2O$ while recovering the latent heat. At the same time, the FGC has a potential for high-efficiency removal of $SO_x$ and $NO_x$ by exploiting their good solubility in water. In this study, experiments were carried out in a lab-scale, direct contact FGC under different pressures varying between 1 and 20 bar to evaluate the removal efficiency of $SO_2$ and $NO_x$ for individual gases and their mixture. In the tests for individual gases, 20% and 76% of $NO_x$ was removed at 1 bar and 10 bar, respectively. Even higher removal efficiencies were achieved for $SO_2$, and also these were maintained for longer as the pressure increased. In the tests for $SO_2$ and $NO_x$ mixture, the removal efficiency of $NO_x$ increased from 13% at 1 bar to 56% at 20 bar because of higher solubility at elevated pressures. $SO_2$ in the mixture was initially dissolved almost completely and then increased by 1,219 ppm at 1 bar and by 165 ppm at 20 bar. Overall, the removal efficiency of $SO_2$ and $NO_x$ was increased at elevated pressures, but it was lower in the mixture compared with individual gases at identical conditions because of a lower pH and associated chemical reactions in water.

• Journal of Life Science
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• v.29 no.2
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• pp.239-247
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• 2019

The aim of this study was to improve the efficacy and functionality of Viola mandshurica (VM). A water suspension of VM power was fermented for 72 hr with Bacillus methylotrophicus CBMB205 (BM) and Leuconostoc pseudomesenteroides NRIC1777 (LP) isolated from kimchi. The antioxidant activity and reducing power of fermented VM, its total phenolic and flavonoid compounds, as well its inhibitory activity on ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase were determined and compared to those of non-fermented VM (NVM), a negative control. The total phenolic and flavonoid compounds of VM fermented with BM and LP were higher than those of NVM by 1.4, 1.17, and about 3 times. There was no difference in 2, 2'-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity between fermented VM and NVM. However, there was a 2.1- and 1.6-fold increase in 2, 2'-azino-bis-(3-ethylbenzothzoline-6-sulfonic acid) (ABTS) radical scavenging activity in VM fermented with BM and LP, respectively. The reducing power of BM was 1.6 times as high as NVM, but no significant difference was found between LP and NVM. Fermented VM's inhibitory activity on ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase was much higher than that of NVM. Fermenting VM with BM was superior to fermenting it with LP, except flavonoid content. Taken together, VM fermented with BM could be used as a functional food and as an additive to cosmetics.