• Culinary science and hospitality research
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• v.22 no.6
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• pp.14-23
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• 2016

This purpose of this study is to examine the antioxidant and antimicrobial activities of Persicaria hydropiper L. extract in 70% ethanol and in water, a medicinal herb, as an effort to examine the potential of medicinal herbs for development of antioxidants and natural preservative substitutes. The total poly-phenol content in the 70% ethanol extract and in the water extract were 19.88 mg/g and 7.46 mg/g, respectively. The DPPH radical scavenging activity was 90.99% and 64.98% in the 70% ethanol extract and water extract, in which 70% ethanol extract showed a higher activity. The antioxidant effect of Persicaria hydropiper L. extract appears to be very good and due to its excellent growth inhibitory effect on food-poisoning-causing microorganisms in the food, it is thought to be utilized as a potential natural preservative substitute in many areas.

• Journal of Korean Society on Water Environment
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• v.38 no.3
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• pp.133-142
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• 2022

Natural organic matter (NOM) is a heterogeneous mixture of organic matter with various polarities and molecular weights in an aquatic environment. This study investigated the effects of separation conditions (resin volume, organic matter, etc.) and the repeated use of the resin for the fractionation of organic components in the DAX resin fractionation method. The distribution characteristics of the organic components ((hydrophilic [Hi], hydrophobic acid [HoA], and hydrophobic neutral [HoN]) under the derived fractionation conditions were also analyzed. Constant fractionation results (i.e. HoA/Hi ratio) were obtained in the column capacity factor (i.e. the packed resin volume) in the range of 50 to 100. The resin-packed column maintained constant separation efficiency for up to two repeated uses. The above conditions were applied to wastewater and stream water samples (before and after rainfall). The results showed that the concentration of organic matter in the wastewater effluent was 2-15 times lower with an increased ratio of hydrophilicity to hydrophobicity (i.e. Ho/Hi) compared to the influent depending on the industrial wastewater classification. Particularly, HoN was found to have a high content distribution, 10.2-50.4% of the total dissolved organic matter (DOM), in the effluents. For the stream water, the content of Hi or HoN increased significantly after rainfall, suggesting a correlation with the distribution characteristics of pollutants from the stream watershed. The results provide useful data to enhance the reliability of the DAX resin fractionation and its application to environmental samples.

• Journal of Conservation Science
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• v.30 no.4
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• pp.467-480
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• 2014

This study was focused on measurement methods for stone cultural heritages by analyzing Ultrasonic (P-wave) velocity variations according to the water content and anisotropy of rocks. As a result of analyzing of rock properties, the water content and saturation degree were rapidly changed at the beginning of drying and then showed exponential curve which their rates of change gradually decreased. However, P-wave velocity and its rate of change maintained constant values after natural drying of 10 hours. Therefore, the ultrasonic measurement for stone cultural heritages should be performed after natural drying of 10 hours considering the weather and moisture conditions. In addition, the highest values of anisotropy coefficient exhibited in granite and limestone, and indirect method was insensitive to anisotropy compared to direct method. However, all rocks remained anisotropy by indirect method. Accordingly, ultrasonic measurement considering various directions is required. The research results will contribute to customized non-destructive testing and precise diagnosis for lithological characteristics of stone cultural heritage.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.561-568
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• 2002

PFA(Paper Fly Ash) are reclaimed mainly or used in cement industry field as mixture agent in terms of materials recycling. Recently, research for recycling PFA as embankment materials or soil stabilization agent are undergoing in geotechnical engineering field. In this study, physical characteristics of PFA stabilization agent-soil admixtures are examined in change of water content, void ratio, consistency, grain distribution, specific gravity and density. Futhermore, the physical characteristics are compared with unconfined strength as engineering characteristics. Test results showed that unconfined strength and density are increased with increasing of PFA stabilization agent mixed ratio. On the other hand, specific gravity, void ratio and water content are decreased with increasing of PFA stabilization agent mixed ratio. It would be concluded that natural high water content ratio weak soil could be highly improved engineering and physical characteristics with PFA stabilization agent

• Journal of Integrative Natural Science
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• v.6 no.2
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• pp.76-81
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• 2013

ZnO nanoparticles and vinyl pyridine were added to the mixture of MMA (methyl methacrylate), HEMA (2-hydroxy ethyl methacrylate) and NVP (N-vinylpyrrolidone) in a mould at various concentrations. Cross-linker EGDMA (ethyleneglycoldimethacrylate) and AIBN (azobisisobutyronitrile) initiator were finally added to the mixture and then heated at $80^{\circ}C$ for 60 min to prepare high-performance hydrogel ophthalmic lens. The physical properties of the hydrogel ophthalmic material were investigated by measuring the average value of refractive index, water content and optical transmittance. The refractive index of 1.429~1.450, water content of 34~41%, and visible transmittance of 78~90% were obtained. The material is possibly used to manufacture UV-block hydrogel contact lens.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.199.1-199.1
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• 2010

Use of recycled aggregates that are constituents of concrete or asphalt-based structures has become popular because the recycling is an eco-friendly way to overcome the depletion of natural aggregates. In order to adopt the recycled aggregates for backfilling a power transmission pipeline trench, their thermal resistivity should be low enough to prevent thermal runaway in the transmission system. In this study, a series of laboratory tests with QTM-500 and KD2 Pro was performed to measure the thermal resistivity of recycled aggregates prepared from various sources. Relationships between the thermal resistivity of recycled aggregates and the water content have been obtained with consideration of compaction effort. Similar to natural soils, the thermal resistivity of the recycled aggregates decreases with increasing the water content. In addition, this study compared the experimental data with conventional prediction models for the thermal resistivity in the literature, which suggests the availability of the recycled aggregates as backfill material substituting for natural aggregates when backfilling the power transmission pipeline trench.

• Journal of Life Science
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• v.18 no.7
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• pp.958-962
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• 2008

To get the nutritional data of hot water extract from imported kangaroo tails, research was done about contents of collagen, chondroitin sulfate, protein, fat, mineral ions, and conjugated linoleic acid (CLA) in tails. Collagen content of sulfuric acid digested sample was way higher at bones than meats in both kangaroo tail and cow tail. Comparing kangaroo tail and cow tail, meat of kangaroo tail have 1.7 times higher collagen content than that of cow tail. Content of collagen in bone parts of kangaroo tail was also higher 1.2 times than that of cow tail. Meat sample of kangaroo tail (liquid extraction) have 1.3 times higher content of muco-polysaccharide than that of cow tail. In the born part, kangaroo tail was 2.4 times higher than cow tail in its content of muco-polysaccharide. The CLA content of the kangaroo tail showed the content that was higher than 0.9% of the cow tail for 4.9% and showed about 5.3 times high ratios. Especially in kangaroo tail, a band with high content of CLA was found between C18:1 and C18:2.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.78-86
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• 2023

Here, upon acute (96 h) and chronic (14 days) exposure, ingestion of polystyrene NPs (100 nm) and physiological, biochemical, and cholinergic modulations were analyzed in the water flea Moina macrocopa exposed to different concentrations (0.001, 0.01, 0.1, 1, 5, 10, 50, 100, and 500 ㎍ l^-1). Exposed NPs were observed in the internal organs (e.g., digestive tract and foregut) of the water flea. Chronic exposure to the relatively high concentrations resulted in significant decreases in survival, body length, and the total number of molts, whereas reproduction parameter was not affected. Significant increase in oxidative stress biomarker (malondialdehyde) and decrease in the intracellular content of endogenous antioxidant (glutathione) and enzymatic activity of antioxidant enzymes (glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase, and glutathione S-transferase) were detected in response to relatively high concentrations of NPs. Transcriptional expression of the hsp70 gene was increased in response to relatively high concentrations of NPs, whereas acetylcholinesterase activity was lowered by the same concentrations of NPs. Taken together, NPs exposure would be a significant modulator on physiological and biochemical metabolism of water flea.

• Journal of Environmental Health Sciences
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• v.17 no.2
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• pp.95-101
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• 1991

Lead acetate solution were intraperitoneally injected to rats of average body weight 220g to cause lead poisoning. Antidotes were orally administered using catheter to the rats and the urine was collected after 24 hours. ALA in the urine were determined by U. V. spectrophotometer. Antidotes used in this experiment were the water extracts of scutellaria radix and D-penicillamine solution. ALA in the urine was determind by Wada method. It was found that ALA content in the urine was decreased after oral administration of water extracts of scutellaria radix and D-penicillamine solution. In this study it is believed that water extract of suctellaria radix could be used as an excellent antidate in lead poisoning.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.322-325
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• 2003

Controlled hydration treatment of tobacco seeds enhanced seed performance greatly without additional materials associated with conventional osmotic or solid matrix priming technique. The seeds were hydrated by adding water to a level from 10 to 60% by 5% increments and incubated for 8 days at $25^{\circ}C$. After the treatment, the seeds were dried to the original seed moisture content under $20^{\circ}C$ for 72 hours. The moisture content of tobacco seeds equivalent to 35% by the hydration treatment gave the greatest improvement in germination rate and speed compared to untreated or polyethylene glycol (PEG) primed seeds, especially at low temperature of $15^{\circ}C$.