• Explosives and Blasting
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• v.33 no.3
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• pp.21-28
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• 2015

The objective of this study is to develop a method for monitoring continuously the combustion propagation behavior of commercial thermite reaction mixtures using conventional continuous VOD (velocity of detonation) system. In order to monitor the combustion front propagation with elapsed time during thermite reaction, the VOD system employs two types of commercial VOD probes and one self-made probe: VOD PROBEROD-OS, VOD PROBEROD-HS and VOD PROBEROD-ES, respectively. Among the probes, the only self made VOD PROBEROD-ES successfully demonstrates the velocity of combustion propagation (VOC) with elapsed time. It was found that VOC of the thermite reaction mixture inside a steel tube has been reached around 200m/s within 100mm distance from the ignition and dramatically increased up to about twice the speed of sound in the range between 100mm and 300mm distance. Finally the VOC reached up to around 800m/s. This results imply that it is necessary to use over 300mm long cartridge of thermite reaction mixture in order to achieve normal VOC of the mixture.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.143-149
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• 2014

This study was conducted to evaluate the effects of the mixture ratio of soil amendments blended with coco peat (Coco) and American soldier fly cast (SFC) on the physicochemical properties on the sand green. pH and EC of soil were significantly related to mixture ratio of SFC, Mix1, Mix2 and Mix3. Capillary porosity, air-capillary porosity and total porosity of root zone mixed SFC, Coco, Mix1, Mix2 and Mix3 were met to the USGA green specification. The mixture ratios of Mix1 and Mix2 in root zone were positively related capillary porosity and total porosity, and air-capillary porosity was negatively related capillary porosity and hydraulic conductivity. Capillary porosity of Mix1, Mix2 and Mix3 blended SFC and Coco was affected by SFC and Coco, and total porosity by Coco. These results showed that soil amendments blended SFC and Coco was developed capillary porosity and hydraulic conductivity on the USGA sand green than these of SFC.

• Korean Journal of Organic Agriculture
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• v.27 no.4
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• pp.453-461
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• 2019

The purpose of this study was to evaluate the mixed treatment of compost tea and amino acid liquid fertilizer as a substitute of oil cake for the organic cultivation of maize in Goesan, Chungbuk province. As a result, nitrogen, phosphoric acid, potassium, calcium and magnesium contents of each organic fertilizer were in the order of oil cake > amino acid fertilizer > compost tea. Each of these organic fertilizers had little influence on the change of soil chemical. Individual treatment of amino acid fertilizer and oil cake for weight of an ear as well as all individual treatments for the fresh weight of 100 kernels showed significant increase, compared to the untreated control. For the corn yield of merchantable quality, each treatment of compost tea, amino acid liquid fertilizer and oil cake increased higher 3.9, 5.4 and 5.9% than untreated control, respectively. On the other hand, as a result of mixed treatment of amino acid fertilizer and compost tea, the change of soil chemical property was insignificant. The mixed treatment, Nonetheless, showed significant increase for stem height to 1st ear, grain setting length in an ear, weight of an ear, and fresh weight of 100 kernels, compared to the oil cake as a control. After all, the corn yield of merchantable quality produced by the mixed treatment was 3.9% higher than the control. Therefore, our study would be considered that the mixed treatment of amino acid and compost tea is one of organic materials that can replace oil-cake in maize.

• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.18-28
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• 2009

Both feasibility and accuracy of lumped approach to group 12 organic compounds in mixtures into a fewer number of pseudocompounds in sorption processes were evaluated using mixtures containing organic compounds with various physicochemical properties and low-surface-area mineral sorbents. The lumped approach for sorption to simulated mineral sorbents was developed by cluster analysis from statistics. Using the lumped approach, the sorption estimated from both reduced number of pseudocompounds and their sorption parameters (i.e., $K_f$, n) can approximate sorption behavior of complex organic mixtures. Additionally, the pseudocompounds for various mixtures to different types of low-surface-area mineral sorbents can be estimated a priori from the physicochemical properties of organic compound (i.e., ${\gamma_w}^{sat}$). Therefore, the lumped approach may help to simplify the complex fate and transport model of organic contaminant mixtures, reduce experimental efforts, and yet provide results that are statistically identical for practical purposes. Further research is warranted to enhance the accuracy of lumped approach using the multiple regression analysis considering the H-bonding capacity, site concentrations, functional groups for mineral sorbents.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.59-68
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• 2011

Research was initiated to investigate the effect of high water-absorbing polymer on turf grass quality of three major turfgrasses. A total of 12 treatment combinations were used in the study. Treatments were made with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Visual turf grass quality was evaluated in creeping bentgrass (Agrostis palustris Huds., CB), Kentucky bluegrass (Poa pratensis L., KB), and zoysiagrass (Zoysia japonica Steud., Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments in CB, KB, and Zoy. Visual quality ratings varied with mixing rates of SOA and WSP, being maximum 5.6 in differences among them. At the end of study it ranged from 0.3 to 9.6 in CB, 0.3 to 4.0 in KB, and 0.9 to 5.8 in Zoy. Turfgrass quality pattern changed with time after seeding among treatments influenced by WSP rates. From this study, a proper rate of WSP is considered to be 5%, 5~10%, and 5% for CB, KB and Zoy, respectively. In general, overall treatment effect of WSP on turfgrass quality was highly associated with SOA 20% in three turtgrass species. When mixing sand with SOA and WSP for rootzone soil, a proper rate of SOA is considered to be 15 to 20% for CB and KB, while 20% for Zoy of warm-season grass. A further study would be required to investigate the effect of varied, gradual mixing rates of WSP on growth characteristics of turfgrasses grown on mixtures of sand, SOA, and WSP before a field application.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1989.11a
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• pp.16-40
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• 1989

엔진오일 첨가제는 오일 전체의 성질에 영향을 주는 것과 윤활 부품의 표명 성질에 영향을 미치는 것으로 크게 구분할 수 있다. 표면 작용용 첨가제 들의 상호작용은 기대이하의 성능을 발휘하는 경우가 있고 그 원인은 첨가제의 상호작용에 의한 것으로 볼 수 있으므로 가능한 범위내에서 실험적으로 살펴보기로 한다. 현대자동차의 엔진과 변속기에 요구되는 윤활유 성능 특성을 만족시키기 위해서는 기유에 요구되는 적당한 성능을 발휘하기 위한 특수한 첨가제를 넣어주어야만 한다. 그러나 첨가제를 개발하는 과정에서 한가지 첨가제의 특성은 그 자체를 실험한 경우와 매우 상이한 결과가 완전히 혼합된 오일에서 나타남을 경험하게 된다. 이것은 첨가제들 자체의 상호작용에 의한 원인으로 암시되지만 이들에 관련된 연구나 지식은 상당히 제한되어 있다. 따라서 첨가제으 상호작용에 관한 실례를 찾아보고 관련자료를 검토해 보는 것은 의미있는 일이라 생각된다. 윤활오일 첨가제가 오일 자체의 성질에 영향을 주는 것으로 점도 시수향상제, 산화 방지제 같은 것이 있고 마찰 표면 특성에 영향을 미치는 내마모성 첨가제, 극압첨가제, 청정제, 분산제, 마찰 계수 감소제 등으로 크게 구분된다. 오일자체에 영향을 미치는 첨가제는 서로 별개로 작용하지만 그래도 상호 반응을 할 수 있다. 예를 들면 자유기 억제제와 과산화물 분해형식의 산화억제제의 혼합물은 산화억제 성능을 최대화 시켜준다.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.12-17
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• 2003

Potato blackleg disease caused by Erwinia carotovora subsp. atroseptica (Eca) has been a serious problem in Korea. Bactericidal activities of twelve bactericides including antibiotics, copper compounds and oxolinic acid were examined in vitro. Streptomycin, streptomycin sulfate, and oxolinic acid effectively controlled the pathogen at 0.02 mM. However, the pathogen developed resistance to the applied bactericides after 72 hours of incubation. Activity of copper compounds such as copper hydroxide, copper oxide and copper sulfate was lower than that of antibiotics. However, the pathogen did not develop resistant to them. Combinations of streptomycin (0.016 mM, 9.3 ppm) + copper oxide (1.2 mM, 171.6 ppm)/copper hydroxide (1.5 mM, 146.3 ppm); streptomycin sulfate (0.005 mM, 7.0 ppm) + copper oxide (1.2 mM, 171.6ppm)/copper hydroxide (1.5 mM, 146.3 ppm) were found to be effective for the control of E. carotovora subsp. atroseptica.

• Korean journal of food and cookery science
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• v.17 no.4
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• pp.353-358
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• 2001

The leaves of Duchung(Eucommia ulmoides), an oriental medicinal plant, have a peculiar aroma of Chinese medicine and astringent taste, which make the consumer be reluctant to Duchung leaf tea. Therefore, the purpose of this study was to develop a mild flavored Duchung leaf tea by mixing with other plants. The flavor patterns of developed tea were analyzed using an electronic nose. Polygonatum odoratum and Elsholtzia splendens were used for improving the flavor of Duchung leaf tea. The addition of 20, 30 and 40% of Polygonatum odoratum improved the overall acceptance in hedonic sensory evaluation. The flavor pattern of the tea was described by principal component analysis(PCA) and the resistance ratio(R/cub gas/R$\_$air/) of sensors. The PCA plot was also used to explain the mild flavor of the tea, which was extended from the right side(positive value of the first principal component) to the left side(negative value). Analysis by using an electronic nose with metal oxide sensors could be applied to detect whether mixed Duchung leaf tea was acceptable or not.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.563-568
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• 1988

Relative effectiveness of antioxidants with their synergists was investigated by measuring AOM stability of palm oil and beef tallow during heating. TBHQ added at a concentration of 0.02% gave the highest AOM stability to palm oil among the antioxidants tested at the equivalent concentration. Beef tallow with added TBHQ showed a higher AOM stability than those with α-tocopherol$({\alpha}-toc)$ and a mixture of BHA and BHT, but showed a lower AOM stability than those with {$\delta}-rich$ tocopherol$({\delta}-toc)$ and mixed tocopherol(m-toc). Addition of ${\alpha}-toc$ to palm oil and beef tallow increased the AOM stability less than a mixture of BHA and BHT. Palm oil and beef tallow with added ${\delta}-toc$ and m-toc showed higher AOM stabilities than that with ${\alpha}-toc$, and there was no significant difference in AOM stability noted between ${\delta}-toc$ and m-toc. The synergistic effects of citric acid to ${\alpha}-toc\;and\;{\delta}-toc$ and of ascorbyl palmitate to ${\delta}-toc$ was noted higher in beef tallow than in palm oil, while that of ascorbyl palmitate to ${\alpha}-toc$ was higher in palm oil than in beef tallow.

• Membrane Journal
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• v.26 no.2
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• pp.126-134
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• 2016

To produce renewable biomethane from biogas, the properties of physical absorbents such as water, methanol, 1-methyl-2-pyrrolidone (NMP), poly(ethylene glycol) dimethylether (PEGDME), and propylene carbonate (PC) were studied, and PC was applied to membrane contactor systems. Among physical absorbents, PC exhibited a high contact angle of $58.3^{\circ}$ on polypropylene surface, and a PC/water mixture (5 wt%) increased the contact angle to $90^{\circ}$. Furthermore, the PC/water mixture presented higher $CO_2$ absorption capacities (0.148-0.157 mmol/g) than that of water (0.121 mmol/g), demonstrating a good property as an absorbent for membrane contactors. Actual operations in membrane contactors using the PC/water mixture resulted in $CO_2$ removal of 98.0-97.8% with biomethane purities of 98.5-98.3%, presenting a strong potential for biogas treatment. However, the PC/water mixture yielded moderate improved in $CO_2$ removal and methane recovery, as compared with water in the membrane contactor operation. This is originated from insufficient desorption processes to reuse absorbent and low $CO_2$ flux of the PC/water absorbent. Thus, it is requiring optimizations of membrane contactor technology including development of absorbent and improvement of operation process.