• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.1-7
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• 2001

Use of high yield pulp and recycled fiber as raw materials and water system closure result in higher fines content and buildup of organic and inorganic contaminants in white water. These are detrimental for the effectiveness of chemical additives including retention aids. Thus it is imperative to employ a retention systems that maintains its efficiency in closed papermaking system for reducing fresh water consumption. The performance of four different microparticle retention systems including cationic polyacrylamide (C-PAM)/bentonite, highly charged cationic starch (HCS)/silica, C-PAM/micropolymer, cationic guar gum (CGG)/silica was evaluated and compared at three different levels of papermaking system closure. Buildup of detrimental substances in a closed white water system increased cationic demand and finally reduced the performance of retention systems. Cationic starch and guar gums maintained their effectiveness in retention in closed white water systems contaminated with anionic trashes because of their structural rigidity and hydrogen bonding ability. Particularly, cationic guar gums, due its stiffness of molecular structure, appeared perform better than catinonic starch.

• International Journal of Concrete Structures and Materials
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• v.10 no.sup3
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• pp.65-74
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• 2016

During concrete pumping, the migration and redistribution of particles occur in a pipe and the lubrication layer that forms between the bulk concrete and the pipe wall is the governing factor determining the flow behavior. In order to identify flow behavior of pumping, in this study, the viscoelastic properties related to the microstructural behavior of a flocculated suspension were examined by using dynamic oscillatory measurements. Cement paste is assumed to be a constituent material of the lubrication layer and ten cases of mixing design are employed by changing the proportions of mineral admixtures. The relationship between the yield stress obtained from the steady shear test and the dynamic modulus resulted from the oscillatory shear measurement was derived and the implications of the correlation are discussed. Moreover, based on the investigation of the viscoelastic properties with oscillatory measurements, the initial behavior of pumped concrete was analyzed systematically.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.635-638
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• 2005

In this study, the shear box tests are carried out with cement paste in order to quantify the rheological constants. The materials have four level of water-cement ratios in $0.30\~0.45$, with or without high-range water-reducing AE agent. As the results, it was clarified that the rheological constants of cement paste are dependent on the value of shear strain, and the incremental coefficient of yield value is varied with the water-cement ratio and the dosage of high-range water-reducing AE agent.

• The Plant Pathology Journal
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• v.26 no.3
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• pp.289-292
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• 2010

This study used a modified cetyltrimethylammonium bromide (CTAB) method to efficiently extract DNA from the plant pathogenic fungus Cercospora sojina. Total DNA yield obtained by this method was approximately 1 mg/g of mycelia (fresh weight), and the mean ratio of A260/A280 and A260/A230 were 2.04 and 2.1, respectively. The results of random amplified polymorphic DNA (RAPD) analysis, digestion with restriction enzymes, and Southern hybridization indicated that polysaccharides were effectively removed by this method, and the resulting DNA was sufficient for use in subsequent molecular analysis.

• Korean Journal of Pharmacognosy
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• v.7 no.3
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• pp.195-198
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• 1976

Esculin, esculetin-6-glucoside, m.p. $206^{\circ}C$ was isolated from the fresh bark ok Fraxinus chiisanensis $N_{AKAI}$, one of the indigenous plant of the oleaceous family in Korea, in yield 0.09%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.3
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• pp.135-139
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• 1987

The influence of ploidy level on agronomic characteristics in italian ryegrass, Lolium multiflorum Lam, italicum, was studied using diploids (2x) and tetraploids (4x) on the upland of Livestock Experiment Station, Suweon. The results are summarized as follow: 1. Tetraploid cultivars are in general dark green in leaf color and strong glittered. 2. Diploid cultivars are more resistant to cold than tetraploids but degree of resistance to cold depends on cultivars. The di-and tetraploids did not differ in summer survival and coldand heat resistance of di-Itetraploid cultivars were not related. 3. Tetraploid cultivars have larger leaf-blades, more rapid growth and higher leaf ratio to stem by heading than diploids. 4. Tetraploids possess significantly lower dry matter content than diploids. 5 . Fresh- and dry weight of tetraploids are similar with that of diploids but tetraploids are more leafy than diploids. 6. Seasonal yield depends more on the type of the cultivar than on its tetraploid nature.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.646-648
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• 1991

A possibility of utilizing Chinese cabbage, a kind of renewable resources which is frequently overproduced in Korea, for the production of single cell protein was investigated. Saccharomyces cerevisiae and Candida utilis grew well in cabbage juice producing 4.3 and 5.1 g/l of dried yeast cells, respectively. Freezing fresh cabbage prior to juice extraction did not affect the growth of yeasts and the final cell yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.105-108
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• 1979

Compared with ordinary varieties, the cold resistant lines were heavy in fresh weight of seedling, low in stalk elongation. Their leaf-types were complete runner types, and they were high in wintering rate, and were abundant in the branch number and in pod numbers per branch. They were high in the seed yield.

• Journal of the Korean Chemical Society
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• v.58 no.1
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• pp.72-75
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• 2014

In the presence of zeolites, 4,4'-dibromobiphenyl could be region-selectively nitrated by the action of nitrogen dioxide and molecular oxygen. The ratio of 4,4'-dibromo-2-nitrobiphenyl to 4,4'-dibromo-3-nitrobiphenyl could reach 14 in a high yield of 90%. Zeolites could be easily regenerated by heating and reused four times to give the results similar to those obtained with fresh catalyst. Compared with the classic nitration method, no nitric acid and sulfuric acid were used, which suggested that the method was an environmentally economic process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.687-692
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• 1998

To use onion(Allium cepa L.) residue as raw materials of food product, yields of onion-juice according to various extracting methods and optimal extracting condition of quercetin and its related glycosides were carried out. Onion juices gained by the methods of pressing, rotary crushing, freeze pressing and enzyme treatment. The yield by the method of enzyme treatment was higher than others. The yields of juice from fresh onion and heat-treated onion(8$0^{\circ}C$/10min) by pressing were 66% and 83%, respectively. Ethanol extraction of onion was efficient at 75$^{\circ}C$ and acetic acid extraction was proper at 3% concentration for 3 hours at 11$0^{\circ}C$. The onion extract was fractionated in the order of hexane, chloroform, ethylacetate and butanol to test flavonoids. The highest abundant flavonoids were found in ethylacetate and butanol fraction.