• Journal of the Korean Society for Heat Treatment
• /
• v.35 no.3
• /
• pp.130-138
• /
• 2022

In this study, the characteristic of an amorphous fishing weight material according to controlling the alloy type and alloy composition of the glass forming agent added in PbO₂ oxide was investigated. According to the experimental, when the glass forming agent of 15wt%SiO₂-1wt%MgO content was added in β-PbO₂, an amorphous fishing weight substitute having the lowest friction coefficient, excellent corrosion resistance and durability was obtained. The cell number of PbO₂-15wt%SiO₂-1wt%MgO sample incubated in cell culture fluid tended to hardly decrease even after a lapse of 24 hours, It means that the fabricated PbO₂-15wt%SiO₂-1wt%MgO sample is significantly less-toxic and harmless to the human body, unlikely to metallic lead. It is considered that an fabricated amorphous fishing weight substitute proved to have a potential as an eco-friendly material with little marine pollution.

• Journal of Korean Society on Water Environment
• /
• v.26 no.2
• /
• pp.303-310
• /
• 2010

Recently distinguished AOP means technology resolving organic compounds in water to harmless compounds such as $CO_2$ and $H_2O$ by creating OH radical ($OH{\cdot}$) with more powerful oxidation than general oxidants. It has merits which the 2nd pollution is not caused since it uses solar energy, sludge doesn't take place, it can be applied to high-density waste water and it oxidizes non-biodegradable organic compounds more easily. The purpose of the study was to examine about removable characteristics of phenol which was a non-biodegradable organic matter with UV/$O_3$/Catalyst processes which is one out of AOP and to present applicability of photocatalyst and the optimum conditions of treatment. The study regarded initial phenol concentration, initial pH, photocatalyst amount and flow as its conditions. As the results, the test had the highest removable efficiency (92%) when initial phenol concentration was 100 mg/L, initial pH 7, photocatalyst amount 6L and flow 1.5 mg/min. The removable efficiency was increased as much as initial phenol concentration was increased, when initial pH was 7 (neutrality), photocatalyst amount was increased and flow was increased. It was checked that the optimum HRT was 12 hours. Therefore, phenol is enough removable with UV/$O_3$/Catalyst process and its prospect in the future is expected.

• The Journal of the Convergence on Culture Technology
• /
• v.3 no.4
• /
• pp.177-180
• /
• 2017

Recently, as aging progresses rapidly around the world, studies using light (UV-LED, etc.) as a method which is harmless to the human body and less burden on the treatment are continuously being carried out. Especially, in some fields, it is not used in a limited way but it is advantageous to be used in various medical fields such as dermatology, dentistry, otorhinolaryngology, etc. In many advanced countries, various studies using it have been carried out. However, Are far behind in developed countries. Therefore, in this paper, we propose a technology that can provide good quality services to human patients by effectively controlling light module that can be used for medical use by using IoT crawler-based middleware platform.

• Journal of Korea Soil Environment Society
• /
• v.5 no.2
• /
• pp.33-43
• /
• 2000

Mining wastes left without any proper treatment are affecting barren or arable lands where are located near and far from source through various pathway Metals are the only hazardous constituents that cannot be destroyed or altered by chemical or thermal methods and must be converted into the most insoluble and harmless form as possible, which have slower leaching rates than the original species, to prevent their reentry into the environment. Three types of chemical additives used in this study to immobilize heavy metals showed high immobilized capacity (q) and the efficiency (k) in the order of CaO, $Na_2$S.$5H_2$O, and $CaCO_3$. In addition, bentonite was considered as a good additive to remedy AM(Acid Mine Drainage) from the results of the physicochemical characteristics and immobilizing capacity. The Freundlich coefficients (n and k) from adsorption isotherm for the heavy metals adsorbed on 50g Benlonite were calculated.

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

• Biomedical Science Letters
• /
• v.24 no.1
• /
• pp.30-34
• /
• 2018

Silver (Ag) has been widely used in commercial products and medical fields since ancient times because of its antibacterial effect. It is harmless and non-toxic to the human body. For this reason, recent research has actively evaluated antimicrobial activity using silver (Ag). In this study, we investigated the inhibitory effect of a silver-based compound, silver phosphate ($Ag_3PO_4$) on the growth of Staphylococcus aureus and the activation of human immunity. First, the inhibitory effect of $Ag_3PO_4$ on the growth of Staphylococcus aureus was confirmed by a growth curve and a colonyounting method. As a result, the growth inhibitory effect increased as the concentration of $Ag_3PO_4$ increased. Specifically, treatment with $5{\mu}g/mL$ of $Ag_3PO_4$ resulted in no bacteria growth, and the colony-counting method showed a remarkable inhibition. In addition, the expression of cytokine IL-8 by $Ag_3PO_4$ was examined to investigate the cellular immune system activation by $Ag_3PO_4$. After pretreatment of Staphylococcus aureus for 1 hour with $50{\mu}g/mL$ $Ag_3PO_4$, an increased IL-8 mRNA expression resulted. In cells treated with $Ag_3PO_4$, we found that the expression of IL-8 was enhanced in a time-dependent fashion compared to non-treated cells. These results indicate that $Ag_3PO_4$ induces antimicrobial activity against Staphylococcus aureus and activates human immunity. These results are expected to contribute to the future study of the mechanism of silver (Ag) and silver-based compounds in relation to antibacterial activity.

• Journal of Environmental Impact Assessment
• /
• v.21 no.2
• /
• pp.327-338
• /
• 2012

Environmental specimen banks provide the baselines for the scientists and decision makers to do research using the past and present specimens to expect the possible contaminant implications of the future. Many chemicals that are considered harmless now but not found may be found and pose threats in the future. Collected specimens of animals and plants should be conserved without contamination for future analysis. To ensure the availability of samples for the retrospective analysis, the establishment and maintenance of specimen banks in the developing and developed nations has become absolutely necessary. National Environmental Specimen Bank (NESB) established at National Institute of Environmental Research (NIER) in 2009. For the application of NESB, several activities such as standard operating procedures (SOPs) development have been prepared. This study applied the guidelines for sampling and sample treatment of five environmental specimens which had been prepared from 2007 to 2009. The target species were shoots of red pine and Korean pine, leaves of Mongolian oak, eggs of domestic pigeon and muscles and livers of common carp. The NESB will enhance the quality of environmental assessment and environmental monitoring based on real time and retrospective analysis.

• The Journal of Natural Sciences
• /
• v.11 no.1
• /
• pp.143-150
• /
• 1999

A natural dyeing makes fabrics look unique and elegant which cannot be obtain by synthetic dyestuffs. The natural dyestuffs are harmless to human, and it is easy to get them. Also, the natural dyestuffs are environmentally frendly, which is the anther merit for natural dyeing,We investigated dyeability with several fabrics (cotton, wool, ramie, silk and nylon) using an elm bark. We mordants(natural and synthetic). Also, colorfastness in dyed fabrics was estimated by laundering and light. The optimum condition of dyeability in elm bark was 60 min as time, $80^{\circ}C$ as temperature and 1: 40 as bath ratio. The dyeability in silk and nylon was the best among the sample. The treatment of mordants improved the dyeability and colorfastness in silk, wool and nylon. We obtain various color by the mordants.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.1
• /
• pp.45-51
• /
• 2012

This article aims to find method to mix a harmless hardening agent and soil generated during construction to make paving materials. The main purpose of this research is to get rid of the harmfulness(Chromium (VI), etc.) of cement which has been generally and frequently used as a hardening agent and strengthen it so that it can be used for the general foundation solidification and stabilization of civil engineering/construction structures such as dredging soil treatment, marine structure foundation treatment, surface soil stabilization, and river bank erosion prevention. NSS(Natural Stabilizer Soil) used for this study takes as its chief ingredient the mixture of lime and staple fibers extracted from natural fibers. It increases the shearing strength of soil that it improves the support and durability of the foundation and prevents flooding and frost as well. The pH measured to know its eco-friendliness was 6.67~7.15, and according to the migration testing, only Pb and CN were lower than the standards, so it can be said that NSS has almost no harmful components in it. According to the result of uniaxial strength testing, when the mixture ratio of weathered soil to NSS was 6%, about 1,850kpa strength was expressed. And according to the result of CBR. testing to figure out its appropriateness as a paving material, the CBR of the foundation was 4%~6%. But when the mixture ratio of NSS is over 6%, the water immersion CBR. is over 100%; thus, it is expected that it will show great utility as a paving material.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.4
• /
• pp.324-330
• /
• 2018

In accordance with the amendment of the Industrial Safety and Health Act of 2007, Korea completely prohibited the import, distribution and manufacture of asbestos like Europe and Japan. Accordingly, the current problem of asbestos is the safe maintenance and disposal of asbestos construction material, the disposal of asbestos, and the final disposal of asbestos building materials. In the past, Korea used 100,000 tons of asbestos every year, and the building materials using it exceeded 1 million tons per year. These asbestos building materials continued to be used until 2006, and the Ministry predicted that these materials would continue to be maintained until 2044. When the permeable hardening agent is applied to the asbestos building material installed in the pre-pretreatment step for the harmless treatment of the asbestos waste and the dismantling is carried out, the scattering of the asbestos is suppressed in the disassembling step, detoxification treatment conditions can be improved. Therefore, permeable hardeners should be stably penetrated into asbestos building materials. In this study, it is suggested that pre - pretreatment methods for the harmlessization of waste asbestos building materials with medium density level can be presented. In order to efficiently perform pre - treatment for chemical harmlessness in the future, the mixing ratio of permeable hardener and middle water Optimization is the most important factor.