• Applied Chemistry for Engineering
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• v.29 no.3
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• pp.283-288
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• 2018

As the use of environmentally friendly and non-disease natural pigments grows, various methods for extracting natural pigments have been studied. The natural color was extracted from parsley, a vegetable ingredient containing natural dyes. Target color codes of green series of natural dyes extracted as variables #50932C (L = 55.0, a = -40.0, b = 46.0) were set with the pH and temperature of extracted natural color coordinates (of the extracted), and the quantitative intensities of natural dyes were analyzed. During the colorimetric analysis predicted by the reaction surface analysis method, a color coordinate analysis was conducted under the optimal conditions of pH 8.0 and extraction temperature of $60.9^{\circ}C$. Under these conditions, predicted figures of L, a, and b were 55.0, -36.3, and 36.8, respectively, while actual experimental ones confirmed were 69.0, -35.9, and 31.4, respectively. In these results, the theory accuracy and actual error rate were confirmed to be 73.0 and 13.8%, respectively. The theoretical optimization condition of the color difference (${\Delta}E$) was at the pH of 9.2 and extraction temperature of $55.2^{\circ}C$. Under these conditions the predicted ${\Delta}E$ figure was 12.4 while the experimental one was 13.0. The difference in color analysis showed 97.5% of the theoretical accuracy and 4.5% of the actual error rate. However, the combination of color coordinates did not represent a desired target color, but rather close to the targeted color by means of an arithmetic mean. Therefore, it can be said that when the reaction surface analysis method was applied to the natural dye extraction process, the use of color coordinates as a response value can be a better method for optimizing the dye extraction process.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.2
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• pp.75-82
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• 2008

In order to establish environmentally friendly phosphorus(P) and potassium(K) fertilizer application rates for rice cultivation in Korea, a field experiment was conducted in two different characterized paddy soils, higher and lower P and K content in soil from 2005 to 2006 in Suwon, Korea. Chuchong which is typical rice variety in Korea, was selected for experiment. Rice yields in base P-K fertilizer level ($30-30kg\;ha^{-1}$) and no P-K fertilizer level were 97~98% and 93~97% of standard P-K fertilizer level ($45-57kg\;ha^{-1}$), respectively. At the lower content of P and K in immatured paddy soil, the yield of no P plot was decreased by 7% compared to that of standard P-K plot. Significant difference in rice yield and yield characteristics was found neither in standard P-K fertilization plot nor in base P-K fertilization plot. There was no significant difference in P and K uptake at the harvest stage between standard P-K fertilizer plot and base P-K fertilizer plot. Phosphorus and K uptake was slightly decreased in no fertilizer plots compared to standard fertilizer plot. Phosphorus and K use efficiency of rice plant in base fertilizer plot was higher than that in standard fertilizer plot. Available phosphorus and exchangeable potassium content in soil at the harvest stage were increased in both standard and base fertilizer plot. But no significant difference of P and K content in ? was found between standard fertilizer plot and base fertilizer plot. Rice quality characteristics such as proportion of brewers rice, damaged kernel, broken rice, and content of amylose and protein were lowered in the base fertilizer plot than the standard fertilized plot, while the proportion of perfect kernel increased in the base fertilizer plot From the results, we generally recommend the base P-K fertilization ($30-30kg\;ha^{-1}$) instead of standard P-K fertilization ($45-57kg\;ha^{-1}$) for rice cultivation in Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.3
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• pp.43-55
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• 2013

The purpose of this study is to propose a plan that properly organizes urban close-to-nature streams by evaluating the city park functions, ecological functions and landscape functions required for urban stream and setting up space function suitable for the space. The site of this study is Hongjecheon located in Seodaemun gu of Seoul City, whose length of channel spans 6.12km in total. The plan for the construction of close-to-nature streams had been established from late 2003, and the construction was completed. Evaluation Categories and indications were deduced from 4 stages. First, based on theoretical examination, we made a list of stream and park evaluation categories and added Category about Characteristic of urban streams. Next, we set Final Evaluation Categories and indications through the process of goal-relevance, indication verification, merging similar category. Final Evaluation Categories were deduced such as usage demand, usability(city park functions), biodiversity, inhabitation potential, rarity(ecological functions), historical cultural elements, and landscape Quality(landscape functions). As a result of allotting space functions, zones 1 through 4, got high grades at usage demand, was classified as a civic resort district; zones 5 through 6, close to major green area and remained original landscape, as ecological conservation and restoration district; zones 7 through 8, get high grades at usage demand and usability, as environmentally-friendly use district; and zones 9 through 10, many historical cultural elements and view points, and high green possession rate, as stream scenic district. In addition, detail space function and construction plan for each zones were proposed. As a result of this study, proposed space function assignment considering natural characteristics, humanities and social characteristics and landscape characteristics and is expected to be utilized at reasonable spatial planning considering various functions required for urban stream.

• Research in Plant Disease
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• v.20 no.4
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• pp.235-244
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• 2014

Clubroot and Fusarium wilt of cole crops (Brassica oleracea L.) are destructive diseases which for many years has brought a decline in quality and large losses in yields all over the world. The breeding of resistant cultivars is an effective approach to reduce the use of chemical fungicides and minimize crop losses. This study was conducted to evaluate the resistance of 60 cabbage (B. oleracea var. capitata) and 6 broccoli (B. oleracea var. italica) lines provided by The RDA-Genebank Information Center to clubroot and Fusarium wilt. To investigate resistance to clubroot, seedlings of the genetic resources were inoculated with Plasmodiophora brassicae by drenching the roots with a mixed spore suspension (1 : 1) of two isolates. Of the tested genetic resources, four cabbage lines were moderately resistant and 'K166220' represented the highest resistance to P. brassicae. The others were susceptible to clubroot. On the other hand, to select resistant plants to Fusarium wilt, the genetic resources were inoculated with Fusarium oxysporum f. sp. conglutinans by dipping the roots in spore suspension of the fungus. Among them, 17 cabbage and 5 broccoli lines were resistant, 16 cabbage lines were moderately resistant, and the others were susceptible to Fusarium wilt. Especially, three cabbage ('IT227115', 'K161791', 'K173350') and two broccoli ('IT227100', 'IT227099') lines were highly resistant to the fungus. We suggest that the resistant genetic resources can be used as a basic material for resistant B. oleracea breeding system against clubroot and Fusarium wilt.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.568-576
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• 2017

As interest in functionality and environmentally friendly cosmetics is growing in recent years, materials that use safe and effective plant extracts have been developed. Therefore, this study also attempted to check the possibility of the graviola extract, which is known to have various efficacy mainly as a health functional material as a functional cosmetic material. In order to find out the antioxidant activity of graviola, we measured total polyphenol, total flavonoid content and DPPH radical scavenging activity and measured the ROS activity inhibition effect and cytoprotective effect on oxidative stress by treating HDF with hydrogen peroxide cells at an appropriate concentration after checking cytotoxicity in HDF cells. Based on the results of this experiment, the graviola extract was found to contain as high as 26.6 mg(CA)/100g, 14.3 mg(Q)/100g of total polyphenol and flavonoid, which are the antioxidant indexes and to have the high radical scavenging activity. The cell survival rate of the HDF cells was measured, and as a result, no significant cytotoxicity was observed at all concentrations and the experiment was carried out at a concentration of $100{\mu}g/mL$ afterwards. Inhibition of ROS activity in HDF cells induced by hydrogen peroxide was measured and the concentration-dependent inhibition of ROS activity was found and the cell protection effect of graviola was measured after hydrogen peroxide was treated for 4, 24 and 48 hours. As a result, the cell protection effect as high as 89.92% was confirmed at a $25{\mu}g/mL$ concentration up to 24 hours. As these results show that the graviola extract has excellent antioxidant activity, almost no toxicity to HDF cells, an effective activity inhibitory effect on active oxygen generated by hydrogen peroxide and excellent cytoprotective effect, the possibility as various functional materials with antioxidant and cytoprotective effects was confirmed.

• Journal of Life Science
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• v.25 no.2
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• pp.237-242
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• 2015

The use of calcite-forming bacteria (CFB) in crack remediation and durability improvements in construction materials creates a permanent and environmentally-friendly material. Therefore, research into this type of application is stimulating interdisciplinary studies between microbiology and architectural engineering. However, the mechanisms giving rise to these materials are dependent on calcite precipitation by the metabolism of the CFB, which raises concerns about possible hazards to cement-based construction due to microbial metabolic acid production. The aim of this study was to determine target microorganisms that possibly can have bio-corrosive effects on cement mortar and to assess multi-functional CFBs for their safe application to cement structures. The chalky test was first used to evaluate the $CaCO_3$ solubilization feature of construction sites by fungi, yeast, bacterial strains. Not all bacterial strains are able to solubilize $CaCO_3$, but C. sphaerospermum KNUC253 or P. prolifica KNUC263 showed $CaCO_3$ solubilization activity. Therefore, these two strains were identified as target microorganisms that require control in cement structures. The registered patented strains Bacillus aryabhatti KNUC205, Arthrobacter nicotianae KNUC2100, B. thuringiensis KNUC2103 and Stenotrophomonas maltophilia KNUC2106, reported as multifunctional CFB (fungal growth inhibition, crack remediation, and water permeability reduction of cement surfaces) and isolated from Dokdo or construction site were unable to solubilize $CaCO_3$. Notably, B. aryabhatti KNUC205 and A. nicotianae KNUC2100 could not hydrolyze cellulose or protein, which can be the major constituent macromolecules of internal materials for buildings. These results show that several reported multi-functional CFB can be applied to cement structures or diverse building environments without corrosive or bio-deteriorative risks.

• Journal of Life Science
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• v.28 no.11
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• pp.1354-1360
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• 2018

The aim of this study was to develop a simple, environmentally friendly synthesis of silver nanoparticles (SNPs) without the use of chemical reducing agents by exploiting the extracellular synthesis of SNPs in a culture supernatant of Bacillus thuringiensis CH3. Addition of 5 mM $AgNO_3$ to the culture supernatant at a ratio of 1:1 caused a change in the maximum absorbance at 418 nm corresponding to the surface plasmon resonance of the SNPs. Synthesis of SNPs occurred within 8 hr and reached a maximum at 40-48 hr. The structural characteristics of the synthesized SNPs were investigated by various instrumental analysis. FESEM observations showed the formation of well-dispersed spherical SNPs, and the presence of silver was confirmed by EDS analysis. The X-ray diffraction spectrum indicated that the SNPs had a face-centered cubic crystal lattice. The average SNP size, calculated using DLS, was about 51.3 nm and ranged from 19 to 110 nm. The synthesized SNPs exhibited a broad spectrum of antimicrobial activity against a variety of pathogenic Gram-positive and Gram-negative bacteria and yeasts. The highest antimicrobial activity was observed against C. albicans, a human pathogenic yeast. The FESEM observations determined that the antimicrobial activity of the SNPs was due to destruction of the cell surface, cytoplasmic leakage, and finally cell lysis. This study suggests that B. thuringiensis CH3 is a potential candidate for efficient synthesis of SNPs, and that these SNPs have potential uses in a variety of pharmaceutical applications.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.67-76
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• 2021

Biogasification is a technology that produces environmentally friendly fuel using methane gas generated in the process of stably decomposing and processing organic waste. Biogasification is the most used method for energy conversion of organic waste with high moisture content, and is a useful method for organic waste treatment following the prohibition of direct landfill (2005) and marine dumping (2013). Due to African Swine Fever (ASF), which recently occurred in Korea, recycling of wet feed is prohibited, and consumers such as dry feed and compost are negatively recognized, making it difficult to treat food waste. Accordingly, biogasification is attracting more attention for the treatment and recycling of food waste. Korea's energy consumption amounted to 268.41 106toe, ranking 9th in the world. However, it is an energy-poor country that depends on foreign imports for about 95.8% of its energy supply. Therefore, in Korea, the Renewable Energy Portfolio Standard (RPS) is being introduced. The domestic RPS system sets the weight of the new and renewable energy certificate (REC, Renewable energy certificate) of waste energy lower than that of other renewable energy. Therefore, an additional incentive system is required for the activation of waste-to-energy. In this study, the operation of an anaerobic digester that treats food waste, food waste Leachate and various organic wastes was confirmed. It was intended to be used as basic data for preparing the waste-to-energy incentive system through precise monitoring for a certain period of time. Four sites that produce biogas from organic waste and use them for power generation and heavy gas were selected as target facilities, and field surveys and sampling were conducted. Basic properties analysis was performed on the influent sample of organic waste and the effluent sample according to the treatment process. As a result of the analysis of the properties, the total solids of the digester influent was an average of 12.11%, and the volatile solids of the total solids were confirmed to be 85.86%. BOD and CODcr removal rates were 60.8% and 64.8%. The volatile fatty acids in the influent averaged 55,716 mg/L. It can be confirmed that most of the volatile fatty acids were decomposed and removed with an average reduction rate of 92.3% after anaerobic digestion.