• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.306-310
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• 2010

Petroleum visible markers (dye) have been used to distinguish different fuel classes and to prevent illegal mixing. It is difficult to recognize the real color of visible marker when the small amount of petroleum product was mixed in another fuel oil. In this study, we determined the two wavelengths (370 nm, 645 nm) which detect all Korean petroleum visible marker using UV/Vis spectrophotometer. Then we analyzed the visible marker using high performance liquid chromatography (HPLC) in two wavelength detectors. Also, we optimized the analytic method for petroleum visible marker in illegal mixed fuel oil.

• Tribology and Lubricants
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• v.34 no.5
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• pp.191-196
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• 2018

Bunker C is used in heavy-lift ships, furnaces, and boilers for generating heat, and power. Bunker C has only four regulations for quality standards and is rarely inspected in Korea. For these reasons, other oils such as used lubricant oil are commonly blended with Bunker C. This illegal mixture of fuel can damage the boilers, engines and affect the environment adversely. In this study, we investigate the fuel properties and perform atomic analysis of illegal Bunker C blended with used lube oil. The test results show that higher quantities of used lube oil in Bunker C have higher flash points, total acid numbers, copper corruption, solid contamination, and metal components. Further, increasing quantities of used lube oil in Bunker C cause lower viscosity, sulfur, and V content. However, adequate sample (approximately 1 L) is needed to evaluate presence of adulterants in Bunker C, we attempted the SIMDIST analysis. In the SIMDIST chromatogram, the used engine oils are detected for longer retention times than Bunker C owing to the high boiling point. We also quantitatively analyzed the lube oil content using SIMDIST.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.94-101
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• 2014

Approximately 240,000 tons of waste shells are produced annually in the south and west coast of South Korea. Some of these waste shells (oyster, cockle) are recycled as seeding collector and fertilizer, but most are dumped illegally near the coast. One of the alternative solutions that can economically utilize a large amount of these waste shells is to apply them to the production of construction materials. In this research, the basic physical properties of waste shells such as oyster, cockle, clam, manila clam were investigated, and were used to prepare cement mortar with a 25% replacement ratio of sand. According to the results, the 28 day compressive strength of cement mortar with cockle and manila clam shells was similar to that of plain cement mortar. The compressive strength decreased by about 18% when clam was used. However, the cement mortar with oyster shell showed about a 35% reduction in 28-day compressive strength, and two times the absorption capacity of plain cement mortar. The reduction in compressive strength and the increase in absorption capacity were mostly associated with the porous nature of the oyster shell.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.405-412
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• 2016

Illegally adulterated compounds, such as impotency drugs and their synthetic analogues, which have been purported to enhance sexual potency or mood, have been constantly detected in foods including dietary supplements. The adulterated foods with these illegal compounds may threaten public health because their safety and efficacy have not been verified. This study was aimed at investigating illegal compounds in foods and counterfeit products. 54 illegal compounds were assayed using a simultaneous analytical method involving liquid chromatography equipped with photo diode array (LC-PDA) and LC coupled with tandem mass spectrometry (LC-MS/MS). The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision and accuracy. In 48 of 161 samples, we identified 7 different illegal compounds, including sildenafil, tadalafil, chlropretadalafil, demethylsildenafil, dimethyl-thiosildenafil, icariin and yohimbine. When purchasing products marketed for erectile dysfunction or aphrodisiacs, ulmost care should be taken owing to the possible presence of these illegal compounds.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.51-60
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• 2001

연안역 굴양식장에서 발생하여 폐기물로 분류되어 불법으로 버려지는 굴패각을 파쇄하여 혼합한 모르타르 혼합토의 특성을 규명하고자 압축강도 시험을 포함한 다양한 실내시험을 수행하였다. 압축강도시험을 위하여 준비한 모르타르 공시체는 시멘트, 물, 모래 및 굴패각을 다양한 배합비로 혼합하여 제작하였다. 강도시험결과에 따르면 분쇄한 굴패각의 비율이 최대 모래중량의 40%까지 혼합한 경우에도 굴패각을 섞지 않은 일반 모르타르 혼합토에 비하여 압축강도가 크게 감소하지 않았다. 본 연구에서 수행한 압축강도실험을 분석한 결과, 다양한 크기로 파쇄한 굴패각을 적절한 혼합비의 모래 및 시멘트와 배합하여 사용한다면 건설재료로서의 재활용 가능성이 충분한 것으로 판단되었다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.101-108
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• 2015

The quantities of heavy weight waste glass have been progressively increased because of the rapid industrialization and the change of quality of life. And, the most of them are not recycled. The heavy weight waste glass have been treated by illegal dumping or being buried in landfills. Meanwhile, in order to ensure the safety of nuclear power plant structure, the excellent construction materials are socially required for shielding performance. Concrete is the most widely used construction material, the huge amounts of natural resources are required to make concrete. So, it is needed to investigate the possibility of recycling of heavy weight waste glass as concrete material ingredient. In this study, the heavy weight waste glass was evaluated for the applicability as fine aggregate of shielding concrete. From the results, when heavy weight waste glass was replaced as fine aggregate of mortar, shielding performance can be improved due to increasing in unit weight of mortar. It showed that the strength decreased according to mixing of heavy weight waste glass, Non-Washed heavy weight waste glass is more advantageous in the strength development than Washed case.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.531-535
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• 2016

Phlomis umbrosa and Dipsacus asperoides are distinct species, even though they have a similar appearance. Dipsacus asperoides is used as a Chinese medicinal plant for and has bone strengthening and fracture healing but Phlomis umbrosa has no effect on bone growth. Recently, these plants were used in children's food to improve their bone growth, without distinction in food. Intakes of Dipsacus asperoides in food may be dangerous, because it has never been used in food and its safety has never been tested in humans. We developed liquid chromatography with tandem mass spectrometry method to distinguish these plants in food. The method was validated for linearity, limits of detection, limits of quantification, accuracy and precision. In 5 of 17 samples, we identified Dipsacus asperoides, containing loganin $0.19-14.45{\mu}g/mL$, sweroside $0.13-4.61{\mu}g/mL$ and akebia saponin D $0.59-19.29{\mu}g/mL$. The developed method might be useful to identify Dipsacus asperoides in adulterated food.

• Journal of Applied Biological Chemistry
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• v.58 no.4
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• pp.383-387
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• 2015

A duplex polymerase chain reaction (PCR) detection method was developed to authenticate the use of cat and rabbit in food and to prevent unlawful distribution of illegally butchered meat in both domestic and imported food market. Species-specific primers were designed targeting mitochondrial cytochrome b gene. The sizes of PCR products were 191 bp for cat and 101 bp for rabbit, which were relatively small for better application of the detection method on processed foods. Specificities of primers were verified using 21 animal species including cat and rabbit. Limit of detection was examined by serial dilution of the sample DNA and confirmed as 0.005 ng for rabbit and 0.0005 ng for cat using Bioanalyzer. The developed duplex PCR method showed specificity and sensitivity in the identification of two target species.

• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.29-36
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• 1992

This study primarily attempted to establish the method for the determination of the adulteration in the sesame oil. First of all, extensive experiment was conducted to determine the composition of genuine sesame oil prepared from Korean, Japanese, Taiwanese and Chinese sesame seed. Sesamin and sterols in unsaponfiable matter were examined along with fatty acid in saponifiable fraction by Gc. There was no significant difference in the composition of sesamin and sterols in sesame oils prepared from Korean and foreign seeds. The ranges of sesamin and ${\beta}-sitosterol$ against campesterol were 3.32~5.46 and 2.39~2.99 respectively in all samples. Similiar composition of fatty acids was showed in all pure sesame oils, in which the contents were 8.37~lO.09% palmitic acid, 4.61~5.50% stearic acid, 35.24~39.97% oleic acid, 43.04~49.76% linoleic acid, O.21~O.31% linolenic acid and 0.40~O.69% arachidic acid. Among the commercial sesame oils sold in Markets, three sesame oils from Japan revealed low sesamin, high linoleic acid and linolenic acid, and low oleic acid and stearic acid, suggesting the adulteration with soybean oil.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.2
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• pp.20-27
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• 2019

Compared to the development and manufacturing technology of electronic goods, the development of waste glass recycling technology is relatively insufficient, leading to the acceleration of waste of resources and environmental pollution. Although waste glass recycling technology is being actively developed overseas, waste glass recycling technology is insufficient in Korea, leading to the illegal dumping or burial of waste glass. Waste glass has been confirmed to have pozzolan reaction potential when having hydration reaction with cement. Waste glass is also reported to be effective in reducing bleeding and inhibiting the development of hydration heat by improving the physical properties of concrete and the rheology properties of fresh concrete. Therefore, this paper analyzed the strength characteristics and the effect of alkalic-silica reaction on the expansion of shielding concrete that used waste glass as fine aggregate. Where, suitable admixture materials were used as a measure to suppress the expansion.