• Food Science of Animal Resources
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• v.27 no.1
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• pp.35-41
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• 2007

This study was conducted to determine the effect of pH adjustment and addition of sodium chloride (NaCl) on quality characteristics of pork leg surimi. The pork leg surimi was manufactured with one of following pH 3.0 or pH 11.0 adjustment and contained 2% NaCl or not; C (Alaska pollack surimi, two times washing, 0% NaCl), T1 (pork leg surimi pH 3.0 adjustment, 0% NaCl), T2 (pork leg surimi, pH 3.0 adjustment, 2% NaCl), T3 (pork leg surimi, pH 11.0 adjustment 0% NaCl), T4 (pork leg surimi, pH 11.0 adjustment, 2% NaCl). The $L^*$ and W values was increased with increasing of pH value, but the $a^*$ and $b^*$ values lower. The W values were higher (p<0.05) as addition of NaCl, but $a^*$ and $b^*$ values were lower. In textural properties, the cohesiveness was increased with increasing of pH value, however with the exception of springiness all traits were higher (p<0.05) as addition of NaCl. The breaking force and gel strength was increased with increasing of pH value. The breaking force, gel strength and breaking force u deformation were higher as addition of NaCl, but shear force lower. In sensory evaluation, the tenderness was increased with increasing of pH value and all traits of sensory evaluation also were higher (p<0.05) as addition of NaCl. There were no differences in interaction of pH adjustment and without or with NaCl on color, textural properties, breaking force, deformation, gel strength, shear force and sensory evaluation of pork leg surimi. The color, textural and physical characteristics and sensory evaluation ot T2 and T4 were similar to treatment C. Therefore, the pH 11.0 and 2% NaCl addition on process of manufacture of pork leg surimi would be recommended.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.361-366
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• 2019

In this study, microbial contamivation semisulcospira libertine and effect of sedimentation treatment of major bacterial and fungal pathogens were investigated. The total aerobic bacteria, coliforms, Escherichia coli, Staphylococcus aureus, and yeast and mold present in raw and water-dipped Semisulcospira libertine were enumerated using the standard plate count methods on using the standard plate method on potato dextrose agar (PDA), 3M Petrifilm for coliforms / E. coli, 3M Petrifilm for S. aureus, and plate count agar (PCA), respectively. In analysis of microbial contamination of raw Semisulcospira libertine, the total aerobic bacteria, coliforms, and yeast and mold were monitored as 6.40, 2.70, and $6.79{\log}_{10}CFU/g$, respectively. Both E. coli and S. aureus were not detected (detection limit: 10 CFU/g). However, Semisulcospira libertine dipped in ground water for 3 hours had higher contamination levels of all natural indigenous microorganisms than raw Semisulcospira libertine. Especially, E. coli was detected as $2.46{\log}_{10}CFU/g$ in the ground water-dipped Semisulcospira libertine. The total aerobic bacteria in the ground water-dipped Semisulcospira libertine was not significantly reduced (p>0.05) compared to that in the raw Semisulcospira libertine. Moreover, coliforms were significantly increased (p>0.05) in all water-dipped Semisulcospira libertine. Only fungi were slightly reduced (less than 0.2 log) (p>0.05) in the tap water-dipped Semisulcospira libertine by comparison with the raw Semisulcospira libertine. The results of this study suggest that the use of chemical sterilizing agents and other physical methods in the washing stage will be necessary for the microbial reduction in raw Semisulcospira libertine because the use of sediment removal treatment by ground or tap water did not affect the microbiological safety of the raw Semisulcospira libertine.

• Clean Technology
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• v.25 no.3
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• pp.256-262
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• 2019

Hydroxylammonium nitrate (HAN)-based liquid propellants are attracting attention as environmentally friendly propellants because they are not carcinogens and the combustion gases have little toxicity. The catalyst used to decompose the HAN-based liquid propellant in a thruster must have both low temperature activity and high heat resistance. The objective of this study is to prepare an Ru/alumina/metal foam catalyst by supporting alumina slurry on the surface of NiCrAl metal foam using a washing coating method and then to support a ruthenium precursor thereon. The decomposition activity of a HAN aqueous solution of the Ru/alumina/metal foam catalyst was evaluated. The effect of the number of repetitive coatings of alumina slurry on the physical properties of the alumina/metal foam was analyzed. As the number of alumina wash coatings increased, mesopores with a diameter of about 7 nm were well-developed, thereby increasing the surface area and pore volume. It was optimal to repeat the wash coating alumina on the metal foam 12 times to maximize the surface area and pore volume of the alumina/metal foam. Mesopores were also well developed on the surface of the Ru/alumina/metal foam catalyst. It was found that the metal form itself without the active metal and alumina can promote the decomposition reaction of the HAN aqueous solution. In the case of the Ru/alumina/metal foam-550 catalyst, the decomposition onset temperature was significantly lowered compared with that of the thermal decomposition reaction, and ${\Delta}P$ could be greatly increased in the decomposition of the HAN aqueous solution. However, when the catalyst was calcined at $1,200^{\circ}C$, the catalytic activity was lowered inevitably because the surface area and pore volume of the catalyst were drastically reduced and Ru was sintered. Further research is needed to improve the heat resistance of Ru/alumina/metal foam catalysts.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.1-13
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• 2011

The purpose of this study is to consider practical examples of the method of utilizing plant material 'lotus' used by the ancients, and the value and meaning they wanted to get from it. The method of this study to do this is descriptive study to consider and interpret poem and painting reflecting impression and concept world of lotus. Summary of this study is as follows. First, ornamental value of lotus could be divided in effect of group plant and detail value held by the flower, the leaves and the stem. Especially, group plant lotus in large site provides unique landscape differentiated form other flowering plants. As well, another feature of lotus is its high ornamental value spread in detail elements including the flower, the leaves, the stem and the lotus seed. Second, fragrance expressed 'Hyang-won-ik-cheong(香遠益淸)' is an important charm of lotus. Lotus was utilized as olfactory element providing fragrance. The ancients considered lotus fragrance not only for enjoy but as symbolic object comparing noble man's dignity so that they expressed it in poem and painting. Third, lotus was utilized as acoustical element. That is, the sound of raindrops harmonizing the surface of water and wide lotus leaves was called 'hearing lotus fond and rain', enjoying it as classic grace. Fourth, summer play lotus sightseeing was called mind wash up meaning 'washing the mind polluted by the mundane world'. Such poetic taste was widely enjoyed by various classes from general public to royal family. Besides, poetic taste related with lotus is the method of drinking alcohol using the feature of big lotus leave and vacant stem, called 'Beog-tong-ju(碧筒酒)'. And in the Joseon dynasty period, when the distinction between the man and the woman influenced by Confucian, lotus seed and 'lotus collecting song' was important sign to express romance between man and woman. Lotus has been enamored by wide classes transcending cultural background as thought and religion since ancient times. Due to such reasons, various symbolic meaning of lotus and planting examples related to religious facilities as temples could not be considered in various manner is limitation of this study, and which is research project for the future.

• Journal of Wetlands Research
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• v.24 no.2
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• pp.83-92
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• 2022

The amount of the plastic waste has been increasing according to global demand for plastic. Microplastics are the most hazardous among all plastic pollutants due to their toxicity and unknown physicochemical properties. This study investigates the optimal methodology that can be applied to sewage samples for detecting microplastics before discussing reducing microplastics in MWTPs. In this study, the effect of different pretreatment methods while detecting microplastic analysis of MWTP influent samples was investigated; the samples were collected from the J sewage treatment plant. There are many pretreatment methods but two of them are widely used: Fenton digestion and hydrogen peroxide oxidation. Although there are many pretreatment methods that can be applied to investigate microplastics, the most widely used methods for sewage treatment plant samples are Fenton digestion and H₂O₂ oxidation. For each pretreatment method, there were factors that could cause an error in the measurement. To overcome this, in the case of the Fenton digestion pretreatment, it is recommended to proceed with the analysis by filtration instead of the density separation method. In the case of the H₂O₂ oxidation method, the process of washing with distilled water after the reaction is recommended. As a result of the analysis, the concentration of microplastics was measured to be 2.75ea/L for the sample using the H₂O₂ oxidation method and 3.2ea/L for the sample using the Fenton oxidation method, and most of them were present in the form of fibers. In addition, it is difficult to guarantee the reliability of measurement results from quantitative analysis performed via microscope with eyes. A calibration curve was created for prove the reliability. A total of three calibration curves were drawn, and as a result of analysis of the calibration curves, all R² values were more than 0.9. This ensures high reliability for quantitative analysis. The qualitative analysis could determine the series of microplastics flowing into the MWTP, but could not confirm the chemical composition of each microplastic. This study can be used to confirm the chemical composition of microplastics introduced into MWTP in the future research.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.15-25
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• 2023

In this study, silicon sludge from semiconductor dicing process is recycled to fabricate silica nanoparticles, which are applied as dispersing materials for electro-responsive (ER) smart fluid. In specific, metal impurities are removed from silicon sludge by acid washing to obtain the high-purity silicon powder. And then, silica nanoparticles are synthesized by facile hydrothermal method employing the silicon powder as reactant material. To control the size of silica nanoparticles, the reaction time of hydrothermal method is varied as 8, 15, 20, and 30 hours are applied to control the size of silica nanoparticles. Sizes of silica nanoparticles are increased proportionally to the reaction time owing to the increased numbers of hydrolysis and condensation reactions. As-synthesized silica nanoparticles are prepared as electro-responsive smart fluids by dispersing into silicon oil. Silica nanoparticles synthesized by 30 hours of hydrothermal reaction (SiO₂-H30) exhibit the highest shear stress of 21.4 Pa under an applied electric field strength of 3.0kV mm^-1. Such enhancement in ER performance of SiO₂-H30 among various silica nanoparticles are attribute to the reinforcing effect originated from the mixed particle size, which allowing the formation of rigid chain-like structures. Accordingly, this study successfully propose a recycling method of silicon sludge to synthesize silica nanoparticles and their derived ER fluids, which may suggest new possibility to ESG management emphasizing the eco-friendliness.

• The Korean Journal of Physiology
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• v.15 no.1
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• pp.27-36
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• 1981

Relatively little has been done on the metabolic changes of the lung produced by the excessive alcohol ingestion to the point of the acute alcohol intoxication. In the present study, an effort was made to clarify the possible changes of the pulmonary surfactant system by the acute alcohol ingestion. The dynamic pulmonary compliance and the levels of protein and inorganic phosphorus (Pi) of both lung lavage and extract were chosen as the parameters of the pulmonary surfactant activities. The albino rats of both sexes were used, and 1.5 ml of 50% ethanol per 100 g body weight was given by oral intubation, and the experiment was performed at 1, 3, 6, 12, and 24 hours after the alcohol ingestion. The rat was sacrificed by cutting the carotid arteries, and blood sample for the determination of hematocrit(Hct) and the blood alcohol concentration was obtained. Both lungs were completely removed without dammage to the lung tissue, and the pulmonary compliance was measured by the changes of pressure-volume(P-V) curves by inflating or deflating the lung with air. Immediately after the P-V curves were recorded, the lung lavage was obtained by washing the lobes with 15ml of isotonic saline 3 times with a syringe. Next, total lungs were homogenized and filtered to obtain the lung extract. The protein and Pi levels were measured using the lung lavage and extract as the samples, and the lung/body weight ratio(L/B ratio) was also calculated. The results thus obtained were compared with the normal values and summarized as follows. The blood alcohol concentration reached the highest level of $0.71{\pm}0.02\;g\;%$ at 1 hr and gradually decreased until 24 hrs$(0.36{\pm}0.02\;g%)$ after the alcohol ingestion, but all the experimental groups showed significant increase comparing with the normal. The highest Hct value was obtained at 1hr$(64.86{\pm}2.45%)$ and significantly elevated value was continued throughout the experiment. The L/B ratio was significantly lowered from 3hrs until 24hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The pulmonary compliance at inflation and deflation did not change appreciablly from the normal until 3 hrs after the alcohol ingestion but from 6 th hr on, a generally elevated value was observed with a significant value at 12 hrs and gradual recovery to the normal value at 24 hrs after the alcohol ingestion. The protein level of the lung lavage stowed a significantly increased value of $12.36{\pm}0.35\;mg/gm(3rd hr)$, $12.70{\pm}0.74\;mg/gm(12 th hr)$, and $12.65{\pm}0.88\;mg/gm(24 th hr)$, respectively, comparing with the normal value of $10.65{\pm}0.62\;mg/gm$, and the Pi level also showed a similar tendency of significant increase at 12th hr $(7.65{\pm}0.63\;{\mu}mol/gm)$ and 24 th hr$(6.70{\pm}0.36\;{\mu}mol/gm)$ comparing with the normal value of $5.32{\pm}0.20\;{\mu}mol/gm$. The protein level of the lung extract in the alcohol group was generally similar to the normal value with a slight decrease at 1st and 3 rd hr, tut the Pi level of the lung extract was generally increased in the alcohol group, and a significant increase was observed at 6 th hr$(17.77{\pm}1.54\;{\mu}mol/gm)$, 12 th hr$(13.92{\pm}0.78\;{\mu}mol/gm)$ and 24 th hr$(14.57{\pm}0.53\;{\mu}mol/gm)$ of the alcohol ingestion comparing with the normal value of $10.34{\pm}0.37\;{\mu}mol/gm$. From the above, it may be concluded that the acute alcohol intoxication produces the metabolic changes of the lungs by the increased surfactant activities and elevated pulmonary compliance.