• Journal of the Mineralogical Society of Korea
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• v.29 no.2
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• pp.35-45
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• 2016

Clays, which are abundant in nature and eco-friendly, have been utilized throughout human history due to their characteristic physicochemical properties. Recently, a variety of clays such as montmorillonite, kaolinite, sepiolite and layered double hydroxide with or without chemical modification have been extensively studied for potential application in industries. Clays that possess a large specific surface area, high aspect ratio, nanometer sized layer thickness and controllable surface charge could be utilized as polymer fillers after appropriate chemical modifications. These modified clays can improve mechanical and gas barrier properties of polymer materials but also provide sustained antibacterial activity to polymer films. Furthermore, engineered clays can be utilized as scavengers for chemical or biological pollutants in water or soil, because they have desirable adsorption properties and chemical specificity. In this review, we are going to introduce recent researches on engineered clays for potential applications in future industries such as food packaging and environmental remediation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.3
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• pp.135-140
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• 2020

Since the process gas that is essential in the semiconductor process is a harmful gas, it is an essential task to solve it in an environmentally friendly manner. Currently, the cleaning technology used in the semiconductor process is mostly a wet cleaning based on hydrogen peroxide developed in the 1970s, and the SC-1 cleaning liquid for removing particles on the surface uses a mixture of ammonia and hydrogen peroxide. Therefore, environmental problems are caused, and economic problems caused by excessive water use are also serious. For this reason, the products developed through this study are used to decompose the process harmful gas from the chamber outlet into a harmless gas before entering the vacuum pump, or by incineration and the gaseous components are deposited on the pump. I want to solve the problem. In this paper, CPS (Confined Plasma Source) is proposed to save environment and improve productivity by replacing harmful gases (N2, CF4, SF6⋯., Etc) which are indispensable in semi-contamination process with innocuous gases or incineration with plasma, to study.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2637-2642
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• 2011

A new ultrasonic-assisted micellar extraction and cloud-point pre-concentration method was developed for the determination of major saikosaponins, namely saikosaponins -A, -C and -D, in Radix Bupleuri by high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD). The non-ionic surfactant Genapol X-080 (oligoethylene glycol monoalkyl ether) was chosen as the extraction additive and parameters affecting the extraction efficiency were optimized. The highest yield was obtained with 10% (w/v) Genapol X-080, a liquid/solid ratio of 200:1 (mL/g) and ultrasonic-assisted extraction for 40 min. In addition, the optimum cloud-point pre-concentration was reached with 10% sodium sulfate and equilibration at $60^{\circ}C$ for 30 min. Separation was achieved on an Ascentis Express C18 column (100 ${\times}$ 4.6 mm i.d., 2.7 ${\mu}M$) using a binary mobile phase composed of 0.1% acetic acid and acetonitrile. Saikosaponins were detected by ELSD, which was operated at a $50^{\circ}C$ drift tube temperature and 3.0 bar nebulizer gas ($N_2$) pressure. The water-based solvent modified with Genapol X-080 showed better extraction efficiency compared to that of the conventional solvent methanol. Recovery of saikosaponins ranged from 93.1 to 101.9%. An environmentally-friendly extraction method was successfully applied to extract and enrich major saikosaponins in Radix Bupleuri.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.1011-1015
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• 2009

The vegetated porous pavement can be installed as an alternative way to replace the traditional pavement, which contributes less to the water circulation system in the urban area. This study aims to an investigation based on the shadow and pressure of the vehicle system, where the turfgrass get grown and the green block get constructed on the grassy parking lot. This study might achieve these conclusions, in the case of use 'green block' makes grass parking lot, plant a kind of 'zenith' and takes sod thickness 40 mm are more efficient for turfgrass growth in the early times. In the case of parking over 8 hours in a day, after 5 weeks turfgrass growth would come into reduce. So over 4 hours parking and after 9 weeks, we need consider to setting up green block in grassy parking lot. The grassy ground would get pressured by the vehicles' load and it would bring into some damage due to the load after 3 weeks. So we should put the grass's growth root point under the designed a top of 'green block' level. When the vehicle amounts and parking density is in a low level, it could be an environmentally friendly product.

• Journal of Environmental Science International
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• v.17 no.7
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• pp.817-826
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• 2008

Using high voltage electric fields induced by high voltage AC (10-12 kV/cm, 20 kHz) and pulsed (20-30 kV/cm, 40 Hz) electric field generator as a semipermanent and environment-friendly disinfecting apparatus, the disinfection effect of coliform group in the effluent of sewage plant was investigated. The effects of electric field strength, treatment time, discharge area of a discharge tube, water quality factors (electric conductivity, pH and SS) on its death rate were examined. The death rate of coliform group was increased with increasing electric field strength and treatment time. For AC and pulsed electric field generator, the critical electric field strength was 6 kV/cm and 2 kV/cm, respectively, and the critical treatment time was 5 min and 2 min, respectively, regardless of electric field strength. Comparing the death rate of coliform group by AC and pulsed electric fields used in this study, its death rate was higher for the latter than the former, but did not increase linearly with increasing electric field strength. The results obtained for the effects of discharge area, electric conductivity, pH and SS on the death rate of coliform group using AC electric field (12 kV/cm, 20 kHz) were as follows: its death rate showed the trend to increase linearly with increasing discharge area; for the effect of electric conductivity, its death rate was increased with increasing electric conductivity, regardless of ionic species, increased with increasing cationic valency, but was similar between the same cationic valency; the pH $5{\sim}9$ used in this study did not affect its death rate; its death rate was decreased with increasing SS concentration.

• Journal of Environmental Science International
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• v.29 no.8
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• pp.819-826
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• 2020

Production of Bacterial Cellulose (BC) by Gluconacetobacter sp. A5 was studied in shaken culture using different cost-effective carbon sources and its structural and mechanical properties were evaluated. Glycerol showed the highest level (7.26 g/l) of BC production, which was about three times higher than the yield in glucose medium. BC production depended not only on the decrease in pH, but also on the ability of Gluconacetobacter sp. A5 to synthesize glucose from different carbon sources and then polymerize it into BC. All BC produced from different carbon sources exhibited a three-dimensional reticulated structure consisting of ultrafine cellulose fibriles. Carbon sources did not significantly change the microfibrile structure of the resulting BC. BC produced from glucose medium had the lowest water-holding capacity, while BC from molasses medium had the highest. XRD data revealed that all BC were cellulose type I, the same as typical native cellulose. The crystalline strength of BC produced in glucose medium was the highest, and that in molasses medium was the lowest. Our results suggest that glycerol could be a potential low-cost substrate for BC production, leading to the reduction in the production cost, and also to produce BC with different mechanical properties by selecting appropriate carbon source.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.49-52
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• 2008

The plain and simple shape water front structure were designed and installed for wave protection and wave resistance. But the installation of these plain and simple structure cause deficiency of environmental affinity. Also the resonance phenomena from the reflective wave and shipwave of the harbor incident wave caused high tide and wave, consequently maintaining the tranquility of inside harbor, give difficulty for mooring the ship and loading-unloading, increase the possibility of ship collision at the quray wall and landing place To solve these problems, we develop the environmentally friendly wave dissipation block. And installation efficiency, stability of the blocks through experiment of C.E Block Joint.

• KSBB Journal
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• v.31 no.4
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• pp.208-213
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• 2016

Recently, numerous studies have utilized graphene in biomedical applications such as drug delivery, cancer therapy, and bioimaging. In this study, graphene was eco-friendly prepared by liquid phase exfoliation of graphite using plant extracts in water. Initially, 12 different plants or plant parts were screened for the characteristic graphene peak at near 268 nm using UV-Vis spectrophotometric analyses. The ability to form stable black graphene dispersion was highest using Xanthium strumarium extract. Transmission electron microscopy images showed that about 5 layer-graphene was produced from 1 g/L of graphite, while more than 5 layers were formed from 2 g/L of graphite. The optimum X. strumarium concentration for graphene production was 2 g/100 mL.

• Journal of Environmental Policy
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• v.3 no.1
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• pp.71-94
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• 2004

The purpose of this study is to propose a way to develop and disseminate the renewable energy technologies and industries in the local community. Fundamentally, the renewable energy is able to reduce environmental pollution and diminish a use of fossil-fuel energy in the local area. And it will lead to promoting regional sustainable energy in the future, as well as making contributions to local economic development. Above all, based on the environmental conservation project, including greening of the city and improving water quality, Daegu metropolitan city has launched a series of renewable energy projects, such as solar city programs and local energy plan. But, some problems still exist, due to the technological, economic and socio-political barriers. Thus, to encourage and disseminate a renewable energy in Daegu city, we need to examine a present condition on renewable energy and analyze constraint elements to prevent its distribution. Based on the results, we have to set the feasible strategy to develop and disseminate renewable energy in Daegu city and help it systematically integrate renewable energy technologies and industries into environmental economics and city planning. Ultimately, to achieve this purpose, we need to adopt the following policy measures: (1) establishment of a master plan for renewable energy; (2) interconnection between local development project and energy industry; (3) promotion of technological development; (4) inducement of and assistance to renewable energy industry; (5) fostering venture companies; (6) specializing Daegu's public office by energy-specific education programs. In particular, local entities including local company, consumers, policy-makers and citizen's groups have to pay attention to local energy plan for the regional sustainable energy future. These measures will lead to establishing an environmentally friendly and sustainable city.

• Journal of the Korean Society of Costume
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• v.56 no.3 s.102
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• pp.73-80
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• 2006

This study is aimed to produce natural dyeing garments, which contain the sentiments and color sense of Koreans, by using various household supplies, with a view to increase the values added and utilization of natural dyeing. The dyes mainly used for this study are multi-colored ones which are durable after dyeing and can represent various colors. They include Lithodpermum officinale, Caesalpinia sappan, Rubia Cordifolia, Pellodendron Bak, Curcuma Longa L., fallen Ginkgo Biloba, Artemisia Princeps, and Quereus acutissima carr shell. Considering water pollution and other things, aluminum acetate and ferrous chloride were used as mordants. Cheap and practical materials such as cotton cloth and those with traditional patterns and elegance such as silk and ramie fabrics were used to produce baby goods, household supplies, clothes, and accessories. The produced supplies closely contact with our body, so they may have a great effect on human body. The household supplies produced include rug, bedclothes, room bedclothes, curtain, bedding set, cushion, and sunlight blind, in consideration of the functionality or medical actions of the goods which are closely related to the human skin. The infant supplies produced include longcloth for newborn baby, bedding set, gauze handkerchief, and doll. The clothes include night gown, shirt, bath gown, and Korean traditional clothes. The accessories include tablecloth, cup pad, bag, wrapping cloth, mouse and keyboard cushion, and scarf. Nowadays, consumers prefer environment-friendly naturally dyed garments and products. In order to control the naturally dyed garments and products which are traded in the domestic market, it is urgent to introduce such ecological marks as 'Toxproof' and 'Ecoproof.' Currently, many ordinary persons, who are not experts, have interest and participate in natural dyeing, but they simply produce naturally dyed garments, not artistic works or everyday supplies. The present author expects this study will contribute to the production of household goods by such persons. The author also hopes that they will develop and commercialize such designs as suit to modern tastes and senses based on the unique cultural assets of Koreans, so that Korean naturally dyed products may be recognized as reliable commodities equipped with international competitiveness.