• Clean Technology
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• v.25 no.2
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• pp.123-128
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• 2019

$Bi_2MoO_6$ catalysts were successfully synthesized using ethylene glycol monomethyl ether (EGME), glycerol (GL), ethylene glycol (EG), and water as solvents by a conventional hydrothermal method. The synthesized catalysts were characterized by XRD, DRS, BET, SEM, and PL, and we also investigated the photocatalytic activity of these materials for the decomposition of Rhodamin B under visible light irradiation. The XRD results revealed the successful synthesis of 12-18 nm, well-crystallized ${\gamma}-Bi_2MoO_6$ crystals with an Aurivillius structure regardless of solvent. In addition, the $Bi_2MoO_6$ catalysts prepared below $140^{\circ}C$ showed an amorphous phase; however, those prepared above $160^{\circ}C$ showed well-crystallized ${\gamma}-Bi_2MoO_6$ crystals. All the catalysts have a similar absorption spectrum from the ultraviolet region up to the visible region less than 470 nm. This result suggests that all the $Bi_2MoO_6$ catalysts are potential visible-light-driven photocatalysts. The $Bi_2MoO_6$ catalysts prepared using EGME as a solvent showed the highest photocatalytic activity. In addition, the $Bi_2MoO_6$ catalysts prepared at $180^{\circ}C$ showed the highest photocatalytic activity. The PL peaks appeared at about 560 nm at all catalysts and the excitonic PL signal was proportional to the photocatalytic activity for the decomposition of Rhodamin B. This suggests that the stronger the PL intensity, the larger the amount of oxygen vacancies and defects, and the higher the photocatalytic activity.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.587-593
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• 2018

This study was carried out to investigate the effect of roasted rice bran (RRB) on the rheological properties of bread dough. According to farinograph analysis, the consistency of the control sample was greatest. There were no significant differences in water absorption (p<0.05). Lower values of development time, stability, and time to breakdown, which were affected, by the addition of RRB, were observed for RRB-containing dough samples, compared to the control dough sample. Addition of RRB significantly increased the mixing tolerance index (MTI). According to rheofermentometer analysis, the values of H'm, $T^{\prime}_1$, and retention volume decreased with increase in the amount of RRB added. According to the rapid visco analyzer (RVA) analysis, peak viscosity, holding strength, and setback values were greater in the control than in the RRB-containing samples. The addition of RRB to the flour influenced rheological properties like fermentation volume and acidity. The total acidity increased with the increase in the amount of RRB added. The present study has indicated that there was no significant difference between the rheological properties of the control and 5% RRB-containing dough samples. Therefore, the addition of 5% RRB could be an effective way to produce functional flour bread without affecting its desirable physical properties.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.629-635
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• 2018

In this study, the safety aspect of Maesil-cheongs with reduced amygdalin levels was investigated in terms of toxicokinetics and repeated oral toxicity. Plasma or UVC treatment was utilized to obtain Maesil-cheongs with reduced amygdalin levels. The toxicokinetic study demonstrated that the oral absorption of amygdalin decreased remarkably after a single-dose oral administration of both plasma- and UVC-treated Maesil-cheongs. The fourteen-day repeated oral toxicity study revealed that plasma- or UVC-treated Maesil-cheongs did not cause changes in body weight, food intake, water consumption, and absolute and relative organ weights. No significant effects on hematological and serum biochemical parameters were found. Histopathological examination showed no abnormality or toxicological change. These findings suggest that plasma- and UVC-treated Maesil-cheongs have no toxicity potential, and these processes will be useful to obtain products with safe, reduced amygdalin levels.

• Korean Journal of Medicinal Crop Science
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• v.27 no.1
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• pp.30-37
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• 2019

Background: This study was conducted to investigate the changes in the photosynthetic parameters, chlorophyll content, chlorophyll fluorescence, and growth characteristics of Aruncus dioicus var. kamtschaticus seedlings under different shading treatments. Methods and Results: The shading treatment was regulated with the shading level (non-shaded, 35%, 55%, and 75% shading). Photosynthetic activities, such as net photosynthetic rate, stomatal conductance, stomatal transpiration rate, and performance index on absorption basis ($PI_{ABS}$)were the highest under 35% shading ($4.36{\mu}mol\;CO_2{\cdot}m^{-2}{\cdot}s^{-1}$, $54.2mmol\;H_2O{\cdot}m^2{\cdot}s^{-1}$, $0.66mmol\;H_2O{\cdot}m^{-2}{\cdot}s^{-1}$, and 1.3, respectively), and the lowest under 75% shading. This implies that the decrease in net photosynthetic rate may be due to an inability to regulate water and $CO_2$ exchanged through the stomata. Thechlorophylla, b, and a + b contents were increased with elevating shading level and the chlorophyll a/b ratio showed non-significant differences. It was found that the dry weight (leaf, shoot, and whole) was the highest (1.14 g, 0.49 g, and 2.31 g, respectively) under 35% shading and the t/R ratio was the highest under 75% shading. Conclusions: It is concluded that 75% shading exhibited a strong reduction of photosynthetic activity, and 35% shading showed the best conditions for the early growth and cultivation of A. dioicus var. kamtschaticus.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.66-73
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• 2019

Approximately 80% of the mines are vacated or abandoned mines and are mostly left without suitable environmental treatment facilities. In the area around the abandoned mine site, problems such as drainage of acidic city drainage and leakage of leachate occur, and ground subsidence caused by this can cause a safety accident due to sink hole occurrence. In this study, flow, compressive strength, water uptake, pore and hydration characteristics were investigated to investigate the basic properties of liner and cover material based on the replacement ratio of nano silica and silica fume in the existing blast - furnace slag fine powder. As a result, as the substitution ratio of nano silica and silica fume increased, the flow and compressive strength of nano silica specimens increased and the absorption rate decreased. In the case of pore characteristics, the amount of pores decreased as the substitution ratio of nano silica and silica fume increased. Especially, the capillary porosity of 10-1,000 nm diameter decreased. Ray diffraction analysis and SEM measurement showed that the peak positions of the hydration products were almost the same when compared with the 5% alternative test samples of Plain and silica fume.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.221-226
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• 2019

This study investigated the optimal amount of shell powder (0.1, 0.2, 0.3, and 0.4%) to add to rice noodles containing 20% rice flour and compared their quality characteristics to those of wheat noodles containing a commercial alkaline reagent (added at 0.4%). As the amount of shell powder was increased, the L and b values (Hunter's color) increased. The pH, turbidity, and water absorption also increased as the amount of shell powder was increased. However, when the shell powder content exceeded 0.3%, the hardness, chewiness, springiness, and tension tended to decrease below acceptable levels. This might be because the shell powder inhibited network formation. The textural properties and pH value of rice noodles containing 0.2% shell powder were similar to those of the wheat noodles. This suggests that 0.2% shell powder may be the optimal amount to add to rice noodles when used as the alkaline reagent.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.237-242
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• 2019

The purpose of this study was to investigate the optimal amount of alkaline reagent (0.2 or 0.4%) and rice flour (10-40%) for noodle and supplementation, and compare quality characteristics with those of wheat noodles. Texture properties, pH, tension profiles, and cooking quality of noodles supplemented with rice flour and alkaline reagent were measured. Wheat noodles with 0.4% alkaline reagent added displayed increased b values (Hunter's color), pH, hardness, chewiness, tension profiles, and turbidity, and decreased L, and a values, gumminess, weight, and water absorption compared to wheat noodles with 0.2% alkaline reagent added. Hardness and springiness of wheat noodles with 0.4% alkaline reagent added were 35.2 and 0.0118 N, respectively. These values for rice doodles with 0.4% alkaline reagent and 20% rice flour were similar (36.3, 0.0117 N, respectively). This suggests that addition of 0.4% alkaline reagent and 20% rice flour may be the optimal parameters for producing rice noodle.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.214-220
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• 2019

Four rice varieties (Boseogchal for waxy, Baegjinju for medium-waxy, and Seolgaeng and Haiami for non-waxy) were milled to 2% degree of milling (DOM), and physicochemical and sensory properties of 2% milled rice (2% MR) were compared to those of brown rice (BR). No significant differences in the approximate compositions of BR and 2% MR were observed, whereas the grain color of 2% MR was slightly brighter than that of BR. For all varieties, water absorption ratio of BR was significantly increased by milling. The pasting properties of rice varied significantly depending on the variety, but there was no significant difference in peak and through viscosities between BR and 2% MR. Analysis of the texture of cooked rice showed that milling to 2% DOM caused a significant decrease in hardness, but an increase in adhesiveness and stickiness. Cooked Seolgaeng 2% MR scored significantly higher in the sensory evaluation than the corresponding BR. These results suggest that 2% DOM would be useful for improving the sensory properties of cooked non-waxy rice.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.542-547
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• 2021

Glass lined impellers are corrosion resistant to most chemicals, including strong acids, and also have a smooth, non-stick surface, easy to clean and free from impurities in the process. Glass lined home base impeller is a multi-purpose impeller designed to stir a wide viscosity range of liquids from low viscosity fluids to high viscosity fluids, among others, cell culture, yeast culture, and beer fermentation pots, especially used for air-water system breathable stirring. The glass lining for HB impellers, which are simple in structure and competitive in performance, is essential to have upper and lower division in order to make the joint area between the impeller and shaft as small as possible. The upper and lower division of the impeller hardly affects the mixing performance, but the aeration performance. In this study, in order to optimize the shape of the Glass Lining HB impeller, a study was conducted on the effect of the angle between the upper and lower impellers, the clearance between the impellers, and the number of baffles on the aeration power. The optimal shape and baffle plate conditions for the Glass lined HB impeller were derived through the study results that the angle and the clearance between the upper and lower impellers decreased the ration of the power consumption with aeration P_g and that without aeration P₀, P_g/P₀.

• Journal of Life Science
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• v.31 no.3
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• pp.280-286
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• 2021

Oryzalin is a herbicide that disrupts the arrangement of microtubules by binding to tubulin, thereby blocking the anisotropic growth of plant cells. Microtubules and microfilaments are cytoskeleton components that have been implicated in plant growth through their influence on the formation of cell walls. Microtubules also play roles in the sedimentation of amyloplasts in the root tip columella cells; this sedimentation is related to gravity sensing and results in downward root growth in the soil for absorption of water and minerals. However, the orientation of microtubules changes depending on the level of ethylene in plant cells. A recent study reported that oryzalin stimulated ethylene production via 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase and caused a concentration-dependent inhibition of root growth and gravitropic responses. The aim of the present study was to investigate the possibility that oryzalin-induced inhibition might be recovered by the application of inhibitors of ethylene production, such as 10-4 M cobalt ions and 10-8 M aminoethoxyvinylglycine (AVG). The inhibition of root growth and gravitropic response was overcome by 10-20% by an 8 hr treatment with cobalt ions or AVG. These results suggest that ethylene levels could regulate root growth and gravitropic responses in Arabidopsis.