• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.194-200
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• 1993

Grinding experiments for Al 7075 alloy were carried out to study the influence of grinding conditions and supply methods of grinding fluid on residual stress and surface roughness and grinding force. The residual stress was measured by an X-ray method. The supply method of grinding fluid with a guide nozzle has large decrease value of the tensile residual stress and of grinding force than a normal nozzle. In sparking out state of the grinding work, it is desirable to decrease the depth of cut and the workpiece feedrate for improving surface roughness and mechanical properties.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.266-268
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• 2011

본 논문은 폐타이어 열분해 잔류물인 char를 이용하여 수증기 활성화법으로 활성탄을 제조하였다. 활성화 온도가 증가할수록 비표면적은 증가하였으나 활성화 시간에 따른 비표면적은 3시간에서 최대를 보인 후 시간이 지속되면 비표면적은 감소하였다. 본 연구결과, 타이어열분해 잔류물 char를 이용한 활성탄 제조에 있어 최적의 실험조건은 활성화 온도 $850^{\circ}C$, 활성화 시간 3시간, 승온속도 $5^{\circ}C/min$이었으며 이 조건에서 제조한 활성탄의 비표면적은 $517.6m^2/g$으로 나타났다.

• Korean Journal of Environmental Agriculture
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• v.12 no.1
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• pp.9-17
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• 1993

The leaching behavior of $^{14}C-carbofuran$, $^{14}C-bentazon$, and $^{14}C-3,3,4,4'-tetrachloroazobenzene(TCAB)$ in the forms of freshly treated, 3-month-aged, and 6-month-aged residues, respectively, was investigated in a loamy soil column system. The degradation and mobility of pesticides in soil and the possibility of the contamination of groundwater were followed by this approach: The ambient temperature of $15{\pm}2^{\circ}C$, irrigation by the constant-head method on soil columns, and leaching with 1332 ml of simulated precipitation during 90 days. While the fresh residues of $^{14}C-carbofuran$ and $^{14}C-bentazon$ were very mobile, the aged ones were remarkably reduced in their mobility. Fresh and aged residues of $^{14}C-TCAB$ were very immobile, instead. 3-Keto carbofuran phenol(2,3-dihydro-2,2-dimethyl-3-oxo-7-benzofuranol) was the major degradation product present in the leachate from the soil column containing freshly treated $^{14}C-carbofuran$, while no metabolites could be detected in the leachates from the columns containing $^{14}C-bentazon$ or $^{14}C-TCAB$.

• Analytical Science and Technology
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• v.30 no.5
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• pp.234-239
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• 2017

Identifying the components of residues that are not completely burned at the sites of fires site can provide valuable information for tracing the causes of fires. In order to clarify the types of plastic combustion residues found at the scenes of fires, we studied the residue formed after the combustion of polyethylene (PE) and acrylonitrile butadiene styrene (ABS). Plastic samples were burned at 200, 300, 350, 400, and $500^{\circ}C$ for 3 min using a cone calorimeter, and the changes in weight and combustion products were observed. The powder products obtained by lyophilization and pulverization of the combustion products obtained at each temperature were analyzed by a Fourier transform-near infrared (FT-NIR) spectrometer. When the PE samples were burned, the weight did not change up to $350^{\circ}C$, however a significant change in the weight could be measured above $400^{\circ}C$. The principal component analysis (PCA) of the FT-NIR spectra of the PE and ABS samples obtained at each temperature confirmed that the combustion residues at each temperature were PE and ABS, respectively. Therefore, the types of unburned plastics found at the sites of fires can be confirmed rapidly by near infrared spectroscopy.

• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.625-631
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• 2006

Residual stresses in structural materials are stresses that exist in the objective without the application of any service or other external loads. Manufacturing processes are the most common causes of residual stress. To examine the effect and the distribution of residual stress due to press forming and welding in the production of a 600MPa-class steel tube, a residual stress evaluation test was performed. The measurement used the Hole-Drilling Strain Gauge Method and evaluated the distribution of residual stress, which measured a total of 59 places near the welding line.

• Journal of the korean veterinary medical association
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• v.39 no.2
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• pp.147-154
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• 2003

수의사는 동물질병의 예방과 치료뿐만 아니라 축산물의 위생관리 및 안전성확보에 관한 최고의 전문가이다. 또한 축주와 가장 긴밀한 관계를 유지하고 있으며 신뢰관계를 구축하고 있다. 따라서 축산현장에서 올바른 동물용 의약품의 사용과 사양관리에 관해 적극적으로 지도$\cdot$홍보하는 책임있는 수의사의 역할이 잔류예방과 안전한 축산물의 생산을 위한 관건이라 할 수 있다.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.8 no.4
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• pp.62-71
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• 1987

• Proceedings of the Korean Vacuum Society Conference
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• 1997.07a
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• pp.165-165
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• 1997

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.371-376
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• 2009

The fruits of sweet cherry are highly appreciated by the consumer due to their precocity and quality, such as their sweetness, color and sourness. In this study, the hot-water extract and its sequential organic solvent fractions were prepared from domestic Napoleon sweet cherry (Prunus avium L.) to investigate antimicrobial and antioxidant activity. The hot-water extract contained about 40% sugars, and the solvent fraction yields for hexane, ethylacetate (EA), butanol, and water residue were 0.01%, 3.45%, 16.30%, and 80.24%, respectively. Contents of total polyphenol and total flavonoid of the fractions were 1.24~5.24%, and 0~3.76%, respectively. Among the fractions, EA fraction showed the highest total polyphenol and total flavonoid concentrations. Evaluation of antimicrobial activity of the extract and fractions revealed that EA fraction and butanol fraction contained strong antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhimurium with minimal inhibitory concentration (MIC) of 0.5~1.0 mg/mL. But the extract and fractions tested were not active to Pseudomonas aeruginosa. In a while, only hexane fraction showed anti-Candida activity with 0.5~1.0 mg/mL of MIC. The fraction showed strong activity against different multi-antibiotics resistant strains such as C. albicans CCARM 14020. Antioxidative activity assay showed that EA fraction has a strong DPPH scavenging activity and a reducing power. The $IC_{50}s$ of vitamin E and EA fraction were 15.5 and $195.5\;{\mu}g/mL$, respectively. Our results suggest that the fruit of P. avium L. has high potentials with anti-Candida and antioxidative activity.

• Food Science and Preservation
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• v.18 no.4
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• pp.590-596
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• 2011

Pimpinella brachycarpa, called as cham-na-mul in Korea, is an edible popular herb. However, the study of biological activity of P. brachycarpa is still rudimentary in worldwide. In this study, from the cultivated P. brachycarpa, we prepared the methanol extract and its subsequent solvent fractions, and their antimicrobial, antioxidation, and anti-proliferative activities were evaluated. The fraction yields of n-hexane (H), methylene chloride (EC), ethylacetate (EA), butanol (B), and water residue (W) from the methanol extract were 18.71, 0.7, 0.56, 4.57, and 71.51%, respectively. Analysis of total flavonoid and total polyphenol showed that the EA fraction contained the highest contents (89.23 and 200 mg/g), and the W residue has the lowest contents (19.6 and 2.27 mg/g) among the factions. In antimicrobial activity assay, the EA fraction showed a broad-range antibacterial activity, while the H fraction is effective against gram positive bacteria. In antioxidation activity assay, EA and B fraction showed strong DPPH anion and ABTS cation scavenging activities including reducing power, and Hand MC fraction showed effective nitrite scavenging activity (71.43~83.82 ${\mu}g$/mL of $IC_{50}$). In a while, only B fraction showed strong anti-proliferative activity against human colorectal cancer HCT-116 (166 ${\mu}g$/mL of $IC_{50}$) as a dose-dependent manner up to 200 ${\mu}g$/mL. These results suggest that the EA and B fraction of P. brachycarpa could be developed as functional food ingredients.