• Journal of Sensor Science and Technology
• /
• v.17 no.2
• /
• pp.143-146
• /
• 2008

Polymer-coated film SAW sensors have been fabricated and their sensing properties for toxic chemicals have been extensively investigated. Four types of the toxic chemical compounds of hydrogen cyanide(AC), carbonyl dichloride(CG), pinacolyl methylfluorophosphonate(GD), 2,2'-dichlorodiethylthio ether(HD) were used as target gases. SAW sensors using five different kinds of polymers were used to detect toxic chemicals and their gas sensing characteristics were investigated. The polymers used as the sensing materials were polyisobutylene(PIB), polyepichlorohydrin(PECH), polydimethylsiloxane(PDMS), polybutadiene(PBD) and polyisoprene(PIP). The recommendable mixing ratio of PIB, PECH, PDMS, PBD and PIP to solvents were 1:30, 1:40, 1:10, 1:30 and 1:30, respectively. The sensing characteristics of the SAW sensors were measured by using E-5061A network analyzer.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1098-1108
• /
• 2008

Batch type and column type experiments were performed in order to predict adsorption and movement within soil. Clay minerals montmorillonite and kaolinite were respectively added to paraquat which is a cationic compound with long residual time, 2,4-D which is an anionic compound with relatively short residual time and napropamide which is an amphoteric compound. Therefore, it is very important to determine the movements of toxic pollutants in the ground soil to establish measures to prevent soil grounds contamination and to restore contaminated soils effectively, because contamination of soil is getting severe due to these toxic wastes, industrial waste water, and agricultural chemicals, etc. Therefore, in this study, we have carried out column and batch experiments by using general toxic organic compounds as test samples in order to restore contaminated soils effectively as well as to prepare a basic data to develop absorbents that will remove various toxic organic compounds, with a grandiose purpose to prevent contaminations of soil and grounds due to various toxic organic compounds.

• Textile Coloration and Finishing
• /
• v.31 no.1
• /
• pp.33-41
• /
• 2019

In this report, nano-sized catalysts were introduced onto fabric surface to eliminate toxic chemicals assisted by physical adsorption. For chemical removal of toxic compounds, a series of zirconium-containing catalysts were synthesized and treated on fabric to catalyze the hydrolysis and oxidation of target molecules. Antimicrobial was also introduced for the research purpose to prove the compatibility of as-synthesized catalysts with other solutions. Zirconium ligated with hydroxyl group and MOF(Metal-Organic Frameworks) were exploited as catalyst for removal of toxic compounds, while zinc complex was used for an antimicrobial to culminate in a chemical shield. Once fabrics were functionalized, fabrics were washed 2 or 5 times for a washing durability test. The amount of catalyst in textile were measured by ICP-MS and weight increasing ratio of fabrics.

• Analytical Science and Technology
• /
• v.21 no.5
• /
• pp.392-396
• /
• 2008

Acer tegmentosum is a tree used to treat various liver diseases in Korea. There have been some concern regarding the safety of Acer tegmentosum due to some toxic chemical compounds in its stems. Supercritical fluid extraction (SFE) was employed to develop a removing method of toxic compounds from Acer tegmentosum. The toxic compounds were effectively extracted with ethanol modified supercritical fluid $CO_2$. The optimum condition of SFE was 100 bar of pressure, $40^{\circ}C$ of extraction temperature, 3 mL/min of $CO_2$ flow rate, 0.2 mL/min of modifier (ethanol) flow rate.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.4
• /
• pp.706-709
• /
• 2002

Bacterial bioluminescence has been known to be a highly valuable reporter system for its potential application as an effective and simple environmental monitoring method for toxic compounds. In this short report, we constructed a streptomycetes-Escherichia coli shuttle vector-containing bioluminescence system and evaluated its potential application for toxic compounds monitoring. The luxAB biolurninescence genes from Vibrio harveyi were cloned into a streptornycetes-E. coli shuttle vector (named pESK004) and functionally expressed in Streptomyces lividans. The recombinant S. lividans containing pESK004 exhibited an optimal biolurninescence at the optical density ($OD_{600\;nm}$) of 0.4-0.5 and aldehyde concentration of 0.005%. When the recombinant bioluminescence streptomycetes was exposed to a toxic compound such as heavy metals, chlorinated phenols, or pesticides, the bioluminescence was decreased proportionally to the concentration of toxic compound in the assay mixture. The $EC_{50}$ (effective concentration to decrease 50% of the bioluminescence prior to exposure) values in the recombinant biolurninescence streptomycetes for mercury, 2,4-dichlorophenol, and malathion were measured at 2.2 ppm, 144.0 ppm, and 82.4 ppm, respectively. The degree of sensitivity and specificity pattern toward these toxic compounds characterized in this recombinant bioluminescence streptomycetes were unique when compared with previously reported bacterial bioluminescence systems, and this revealed that a recombinant bioluminescence streptomycetes might provide an alternative or complementary system for potential environmental monitoring.

• KSBB Journal
• /
• v.20 no.1 s.90
• /
• pp.55-59
• /
• 2005

Toxicity test for biodiesel (BD), biodiesel-derived neopentyl polyol ester (NPE) lubricant oil base, lubricant oil for diesel engine (LODE) and petroleum diesel (PD) was carried out using microalgae, Chlorella vulgaris. According to the method of OECD 201, the $EC_{50}$ values of BD and NPE were estimated as 84 and 69 mg/L, respectively, which indicates that these compounds are classified as slightly toxic compounds. The $EC_{50}$ values of LODE and PD were measured as 42 and 24 mg/mL, respectively, showing that these compounds are considered as moderately toxic compounds.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10b
• /
• pp.1-1
• /
• 2003

Poisonous mushrooms have attracted much attention of scientists because of the unique chemical structures and the remarkable biological properties of their toxic components. A wide range of compounds has been characterized as toxic principles, and some of them have widened the horizons of chemical and biological research. Therefore, poisonous mushrooms can serve for a resource of biomedical application. We will describe the recent progress of such aspect of poisonous mushrooms.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2003.10a
• /
• pp.1-8
• /
• 2003

Poisonous mushrooms have attracted much attention of scientists because of the unique chemical structures and the remarkable biological properties of their toxic components. A wide range of compounds has been characterized as toxic principles, and some of them have widened the horizons of chemical and biological research. Therefore, poisonous mushrooms can serve for a resource of biomedical application. We will describe the recent progress of such aspect of poisonous mushrooms.

• KSBB Journal
• /
• v.29 no.5
• /
• pp.307-315
• /
• 2014

Recently seaweed polysaccharides have been extensively studied for alternative energy application. Because their producing cost is high and efficiency low, their industrial applications have been limited. The main component of cell wall of red algae represented by Gelidiales and Gracilariales is agar. Red-algae agar or galactan, consisting of D-galactose and 3, 6-anhydro-L-galactose, is suitable for bio-product application if hydrolyzed to monomer unit. For the hydrolysis of algae, chemical or enzymatic treatment can be used. A chemical process using a strong acid is simple and efficient, but it generates together with target sugar and toxic compounds. In an enzymatic hydrolysis process, target sugar without toxic compounds generation. The objective of this review is to summary the recent data of saccharification by chemical and enzymatic means from red seaweed for especially focused on automobile industry.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.7
• /
• pp.2149-2155
• /
• 2012

A metal-free and efficient procedure for the oxidation of alcohols into the corresponding carbonyl compounds has been described using ammonium nitrate in the presence of silica sulfuric acid under mild and heterogeneous conditions. The use of non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are among the advantages of this method.