• Environmental Engineering Research
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• v.24 no.3
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• pp.495-500
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• 2019

Bioremediation of bacterial algae is one of wastewater treatment by utilizing symbiosis of bacterial algae, which is relatively inexpensive and safe for the environment. The aims of this research were: (1) to investigate initial characteristic of boezem water of Kalidami Surabaya, (2) to investigate the effect of potassium (K) element and carbon source addition toward the reduction of $NH_3-N$ content and organic matter in $KMnO_4$ of boezem water. The research conducted in a laboratory in batches without adding aeration. The initial stage of this research was conducting alga culture until it was obtained chlorophyll-a algae concentration of $3.5{\pm}0.5mg/L$. The best result of range finding test was a comparison of boezem water volume with algal which were about 25%:75%. The research conducted in duplo over 18 d. The result of the research can be concluded that boezem water of Kalidami Surabaya for the parameter of pH, temperature, $NH_3-N$, dissolved oxygen, chemical oxygen demand, biological oxygen demand, and number of $KMnO_4$ show that it enables to do bioremediation of bacterial algae. Decrease efficiency occurred in a reactor with the addition of element K 3% and source C. $NH_3-N$ and $KMnO_4$ final content 0.164 mg/L and 30 mg/L, respectively.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.213-221
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• 2019

Anaerobic digestion (AD) has been widely used to valorize food waste (FW) because of its ability to convert organic carbon into $CH_4$ and $CO_2$. Korean FW has a high content of fruits and vegetables, and efficient hydrolysis of less biodegradable fibers is critical for its complete stabilization by AD. This study examined the digestates from different anaerobic digesters, namely Rs, Rr, and Rm, as the inocula for the AD of vegetable waste (VW) and cellulose (CL): Rs inoculated with anaerobic sludge from an AD plant, Rr inoculated with rumen fluid, and Rm inoculated with anaerobic sludge and augmented with rumen fluid. A total of six conditions ($3\;inocula{\times}2\;substrates$) were tested in serial subcultures. Biogas yield was higher in the runs inoculated with Rm than in the other runs for both VW (up to 1.10 L/g VS added) and CL (up to 1.05 L/g VS added), and so was biogas production rate. The inocula had different microbial community structures, and both substrate type and inoculum source had a significant effect on the formation and development of microbial community structures in the subcultures. The overall results suggest that the bioaugmentation with rumen microbial consortium has good potential to enhance the anaerobic biodegradability of VW, and thereby can help more efficiently digest high fiber-content Korean FW.

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.566-574
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• 2021

This research was carried out to investigate the correlation between soil chemical properties and bioactive compounds of Acer tegmentosum Maxim. The methods of determining bioactive compounds were determined by high performance liquid chromatography, that contained (-)-gallocatechin (0.04±0.01 ~ 0.43±0.28%), salidroside (0.90±0.06 ~ 3.86±0.59%), tyrosol (0.03±0.00 ~ 0.43±0.00%), (-)-catechin (0.05±0.01 ~ 0.37±0.14%), 6'-O-galloylsalidroside (0.02± 0.01 ~ 0.31±0.06%), (-)-epicatechin-gallate (0.01±0.00 ~ 0.04±0.01%). The soil chemical properties analysis such as soil pH, electric conductivity (EC), organic matter (OM), total nitrogen (TN), available phosphate (Avail. P₂O₅), exchangeable cation and cation exchange capacity (CEC) were performed following the standard manual. The correlation analysis between soil chemical properties and bioactive compounds of A. tegmentosum, soil pH, available phosphate and exchangeable cation (Ca²⁺ and Mg²⁺) were negatively correlated with content of salidroside. On the other hand, soil exchangeable cation (Na⁺) showed positive correlation with content of salidroside. The results of this study was able to investigate the correlation between soil chemical properties and bioactive compounds of A. tegmentosum.

• Membrane and Water Treatment
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• v.13 no.2
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• pp.97-104
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• 2022

With a small particle size, specific surface area and chemical nature, Pd/Cu-Fe nanocomposites can efficiently remove the organic compounds. In order to understand the applicability for in situ remediation of contaminated groundwater, the degradation of p-nitrophenol by Pd/Cu-Fe nanoparticles was investigated. The degradation results demonstrated that these nanoparticles could effectively degrade p-nitrophenol and near 90% of degradation efficiency was achieved by Pd/Cu-Fe nanocomposites for 120 min treatment. The efficiency of degradation increased significantly when the Pd content increased from 0.05 wt.% and 0.10 wt.% to 0.20 wt.%. Meanwhile, the removal percentage of p-nitrophenol increased from 75.4% and 81.7% to 89.2% within 120 min. Studies on the kinetics of p-nitrophenol that reacts with Pd/Cu-Fe nanocomposites implied that their behaviors followed the pseudo-first-order kinetics. Furthermore, the batch experiment data suggested that some factors, including Pd/Cu-Fe availability, temperature, pH, different ions (SO42-, PO43-, NO3-) and humic acid content in water, also have significant impacts on p-nitrophenol degradation efficiency. The recyclability of the material was evaluated. The results showed that the Pd/Cu-Fe nanoparticles have good recycle performance, and after three cycles, the removal rate of p-nitrophenol is still more than 83%.

• Food Science and Preservation
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• v.30 no.1
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• pp.1-14
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• 2023

In this study, the nutritional compounds present in various parts of Hovenia dulcis Thunbergii (H. dulcis) were compared. Regarding the free sugar content, fruits exhibited the highest fructose concentration (9.42 g/100 g), whereas branches (2.46 g/100 g) and leaves (5.82 g/100 g) contained the highest glucose levels. The most common types of organic acids were citric and tartaric acids in the fruits, citric and malic acids in the branches, and malic and succinic acids in the leaves. The leaves exhibited the highest total amino acid content of 12,102.91 mg/100 g, whereas vitamin C is predominantly found in branches and leaves at 367.85 mg/100 g and 336.21 mg/100 g, respectively. In H. dulcis, β-carotene was present in high concentration in leaves (2.41 mg/100 g), whereas the branches (0.15 mg/100 g) and fruits (0.09 mg/100 g) contain smaller amounts of it. Vitamin E, α-tocopherol, was present in high concentrations in the fruit (11.01 mg/100 g), branches (6.61 mg/100 g), and leaves (11.01 mg/100 g).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.3
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• pp.104-113
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• 2024

This study aims to examine domestic research trends on technoparks and to explore future research directions in this field. For this purpose, 493 articles were collected from academic journal sites, covering the period from 1997, when the pilot technoparks were designated, to 2022. To avoid duplication of identical titles and content, theses and conference papers were excluded. Only articles registered or candidate-registered in the Korea Citation Index (KCI) were selected. After reviewing the research topics and content, a total of 74 papers were used for the final analysis. The data analysis involved descriptive analyses of the research period, research areas, research methods, research subjects, and research topics. Furthermore, a word cloud text analysis was conducted using 305 keywords related to technoparks. This study is significant as the first comprehensive analysis of research trends on technoparks and aims to provide meaningful foundational data to explore future directions for research and innovation policy related to technoparks.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.4
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• pp.29-43
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• 2024

The purpose of this study was to analyze the soil on two waste areas that lack plants to find out the limiting factors of plant introduction, and to find out the possibility of plant introduction through plant growth experiments by mixing the two waste soil. In the case of tungsten waste soil, insufficient organic matter, water content, effective phosphoric acid, and nitrogen content were the limiting factors for plant introduction, and in the case of coal waste soil, low pH of the soil acted as the limiting factors for natural introduction. Growth experiments showed that the number of leaves of Ipomoea nil grown in soil mixed with both waste soil was 2.7 times greater than that of Ipomoea nil grown in tungsten waste soil, and 2.29 times greater than that of Ipomoea nil grown in coal waste soil. The fresh weight comparison showed that Ipomoea nil grown in soil mixed with the two waste soil had a fresh weight of 2.64 times higher than that of tungsten waste soil and 2.45 times higher than that of coal waste soil. There was no significant difference in the fresh weight of Ipomoea nil grown in soil mixed with the two waste soil and in general soil. Therefore, when the two waste soil are mixed, it can be judged that the components unfavorable to growth complement each other, improving the soil and being effective in plant growth.

• Journal of Integrative Natural Science
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• v.17 no.3
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• pp.67-73
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• 2024

Hydrophilic contact lens was prepared by dispersing MXene material in a hydrogel mixture, and the purpose of this study was to evaluate its properties as an ophthalmic material. The MXene used in the experiment was manufactured through an etching process using titanium aluminum carbide 312 [Ti3AlC2] and hydrofluoric acid [HF]. For the preparation of hydrophilic contact lenses, 2-hydroxyethyl methacrylate [HEMA], a photoinitiator 2-hydroxy-2-methylpropiophenone [2H2M], and a cross-linker Ethylene glycol dimethacrylate [EGDMA] were used, and UV-rays was irradiated for 50 seconds for photopolymerization. Optical transmittance, refractive index, water content, contact angle, electromagnetic wave shielding ability, and photo-thermal conversion effect were measured to evaluate the physical properties of the manufactured contact lens. Compared to MXene materials, MXene mixed with Dimethyl sulfoxide [DMSO] had superior dispersion ability in organic solvents, and the transparency of the prepared hydrophilic contact lenses was high. MXene did not significantly affect the refractive index and water content, and improved the wettability of the contact lens. In addition, the MXene material used as an additive showed electromagnetic wave shielding ability and photo-thermal conversion effect based on its excellent electrical conductivity. It is judged that the mixture using MXene as an additive can be used as a functional contact lens material for electromagnetic wave shielding and ocular photo-thermal therapy.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.41-50
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• 2005

An organic acid tolerance mutant (M-200) was obtained from Leuconostoc mesenteroides KCCM 35471, followed by the screening procedure using a specific organic acid medium (lactic acid: acetic acid, 2:1). The characteristics of the acid tolerance M-200 and the wild type LM-W were examined at various temperature and pH ranges $(l0-30^{\circ}C$ of temp, 3.5-4.5 of pH). The growth of strain M-200 at HCl adjusted medium $(10^{\circ}C\;and\;pH 3.5)$ was observed. In the case of organic acid adjusted medium, the strain showed its growth at the pH range of 3.8. When the strain M-200 was used as a starter for Kimchi fermentation, a constant acid level (0.55) was observed during the whole fermentation period. This result indicates that the strain produces a proper level of acid content for the Kimchi fermentation. This result also indicates that the edible period of Kimchi can be extended to 3.5 fold compare to the result obtained from the LM-W used Kimchi fermentation. However the excess use of the strain M-200 showed the inhibition of growth of Lactobacillus plantarum, low lactic acid level content and low level of organoleptic test. In the case of organic acid content during the Kimchi fermentation, the strain M-200 showed relatively low production rate compare to the wild type (M-200: 3.5 mg/L at 21 days of fermentation, LM-W: 7 mg/L at 21 days of fermentation). Therefore a mixed Kimchi starter containing M-200 and other strains probably maintain a good Kimchi quality during the fermentation.

• Korean Journal of Organic Agriculture
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• v.17 no.4
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• pp.519-527
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• 2009

The main nutritional problem of sorghum$\times$sudangrass hybrid silage is low quality and dry matter (DM) contents. This experiment was conducted to evaluate whether field pre-wilting treatment of sorghum$\times$sudangrass hybrid silage increases DM content and forage quality of the silage. The experiment was a randomized complete block design with three replications. The treatments were consisted of five different wilting days: 0 day (direct cut silage), 0.5 day, 1 day, 2 days and 3 days. Sorghum$\times$sudangrass hybrid silage with pre-wilting showed low 4.00 pH values, however direct cut silage (control) showed a 4.30 value because of its high moisture content. The DM content of sorghum$\times$sudangrass hybrid silage with pre-wilting was high above 25.1% after 1 days, however that of direct cut silage had 17.6%. And the effluent of wilted silage was decreased with prolonged wilting period, but that of direct cut silage produced effluent of 183 mL/kg. Crude protein and ether extract with wilted silage were decreased, however crude ash was increased with prolonged wilting period. Silage with pre-wilting had higher acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control silages, while its non-fiber carbohydrate (NFC) showed the opposite results. Lactic acid and total organic acid were increased with prolonged wilting period. For the palatability of dairy goat, silage with 2 days wilting was highest among silages. The experiment results indicate that wilted sorghum$\times$sudangrass hybrid silage could be recommended as effective method for reducing effluent, increasing pH and forage quality more than direct cut silage. Optimum pre-wilting day of sorghum$\times$sudangrass hybrid silage may be 1 days.