• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1159-1164
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• 2006

In this paper an artificial neural network model is developed to estimate the unconfined compression strength of Deep Cement Mixing(DCM) treated soil. A database which consists of a number of unconfined compression test result compiled from 9 clay sites is used to train and test of the artificial neural network model. Developed neural network model requires water content of soil, unit weight of soil, passing percent of #200 sieve, weight of cement, w-c ratio as input variables. It is found that the developed artificial neural network model can predict more precise and reliable unconfined compression strength than the conventional empirical models.

• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.195-199
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• 2003

Extracts of Escherichia coli as a elicit were treated to suspension cultures of Streptanthus tostus in order to observe the effect on the pholem development. By the elicit treatment, cell wall, sieve endoplasmic reticulum (SER) and p-protein were normally synthesized, but the structure of amyloplast was changed from a round form to irregular and swollen unhalthy form with a tiny starch granular. Oil drops were new synthesized and accumulated in a large oleoplast and proteins were also accumulated in a single membrane. The concentration of sucrose in the phloem, which was induced during the elicit treatment, was higher than normally developed phloem cells. These results suggest that phloem cells might be changed in the normal cycles of metabolism of lipids, carbohydrates and proteins to overcome during the eilicit stress.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.688-692
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• 2001

Three-dimensional experimental analyses were conducted in the pulverizer simplified isothermal model. The experimental model was constructed on a 1/3.5 scale of 500MW pulverized coal boiler. The purpose of this study is to investigate the characteristics of coal particle separator and the pressure loss in the pulverizer models with dynamic classifier. Without regards a shape of separator top, the results showed that the increase of dynamic classifier rpm was induced in finer coal particle. But the capacity of total mass per minute was reduced. Also, the increase of dynamic classifier rpm had no effect on total pressure loss, but an increase of inlet velocity was induced that the rise of total pressure loss in the pulverizer models with dynamic classifier.

• Computers and Concrete
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• v.5 no.1
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• pp.75-88
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• 2008

This paper presents a mathematical model for strength and porosity of mortars made with ternary blends of ordinary Portland cement (OPC), ground rice husk ash (RHA) and classified fly ash (FA). The mortar mixtures were made with Portland cement Type I containing 0-40% FA and RHA. FA and RHA with 1-3% by weight retained on a sieve No. 325 were used. Compressive strength and porosity of the blended cement mortar at the age of 7, 28 and 90 days were determined. The use of ternary blended cements of RHA and FA produced mixes with good strength and low porosity of mortar. A mathematical analysis and two-parameter polynomial model were presented for the strength and porosity estimation with FA and RHA contents as parameters. The computer graphics of strength and porosity of the ternary blend were also constructed to aid the understanding and the proportioning of the blended system.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.288-292
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• 1963

The rates of reaction of various Korean anthracites with carbon dioxide were measured at temperatures ranging from $850^{\circ}C$ to $1100^{\circ}C$ with coal -6, +8 sieve size and the residence time of reactant gas in the fixed coal bed 14.0 to 15.0 seconds. The primary variables studied were the coal sources and temperature. The reactivity was considerably varies with the coal sources and the general trends show that the reactivity sharply increases with increasing reaction temperature except the Yongwol coal where the increase is not so sharp, which is considered to be due to high reactivity and high-pore structure of the coal. It was also found that a straight line was produced when a logarithm of the rate constant is plotted against the reciprocal of the absolute temperature up to 1000^${\circ}C$, but above that temperature it deviates from linearity. The information obtained will be of value in the design of the coal gasifier using Korean anthracites.

• Journal of Industrial Technology
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• v.16
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• pp.105-112
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• 1996

This paper presents coal mine waste (CMW) for use in concrete manufacture as a replacement of normal aggregates. The CMW in this study was collected from Sabook, Jungson-kun, Kangwon-do. Fine and coarse asggregates from CMW were prepared by crushing it in a jaw crusher and separating debris with #4 sieve. CMW aggregates showed good physical and mechanical properties with having specific gravity over 2.65, absorption less than 1%, and abration ratio below 20%, but particle shape of CMW was long or flat, which caused a poor workability in mixing. Therefore, to make workability better, a 1/4 of CMW coarse aggregate was replaced with normal aggregate which had a good particle shape, and a superplasticizer was added to the mix. Compressive strength and other mechanical properties of CMW concrete was very good. In conclusion, characteristics of CMW concrete was acceptable for use as a concrete structural material.

• Animal cells and systems
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• v.13 no.2
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• pp.153-160
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• 2009

The fine structural characteristics of the silk spinning apparatus in the titanoecid spiders Nurscia albofasciata have been examined by the field emission scanning electron microscopy (FESEM). This titanoecid spiders have a pair of medially divided cribella just in front of the anterior spinnerets, and the surface of the cribellum is covered by hundred of tiny spigots which produce numerous cribellate silk fibrils. The cribellar silks are produced from the spigots of the sieve-like prate. and considered as a quite different sort of catching silk with dry-adhesive properties. The other types of the silk spigots were identified as follows: ampullate, pyriform and aciniform glands. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another 1-2 pairs of minor ampullate glands supply the middle spinnerets. In addition, the pyriform glands send ductules to the anterior spinnerets, and two kinds of the aciniform spigots feed silk into the middle (A type) and the posterior spinnerets (both of A & B types), respectively.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.85-91
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• 1981

Ginseng seeds were gathered from 3,4,5 and 6 years of age and were classified into four qroups (below 4mm, 4∼5mm, 5∼6mm and above 6mm in across sieve). They were sown in seedling bed and some characters were investigated in each qroup of seed size. 1. The distribution of seed size of below 4mm, 4-5mm, 5-6mm and 6mm were 23.7%, 60.8%, 12.4% and 4.5%, respectively. 2. The ratio of seed coat dehiscence was not affected by seed size but emergence ratio and emerging vigor were superior in large seed. 3. The large seed showed superiority in stem length, stem diameter, leat and also in root length, root diameter and root weight. but diseased root was not affected by seed size. The effect of age(seed harvest) was not significant on all those characters.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.384-385
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• 2006

• Applied Microscopy
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• v.17 no.1
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• pp.161-168
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• 1987

The elongated filamentous haustorial cells, hyphae, of Cuscuta australis R. Brown penetrated into the vascular tissues of the host plant Trifolium repens L. were studied by the light and electron microscopes. The hyphae reached the host xylem were invaded into the host vessels and then they grew within the host vessels. Finally these hyphae were differentiated into the water conducting elements, xylary hyphae, by thickening of the secondary walls. The hyphae reached the host phloem were branched at the apical regions. These hyphae possessed thin-layered cytoplasm involving the typical features of sieve elements such as the parallel arrays of smooth endoplasmic reticulum, plastids with the clusters of fine starch granules, and mitochondria with the dilated cristae. It was indicated that these hyphae were differentiated into the nutrients conducting elements, phloic hyphae. The structures described were compared with those of other parasitic plants and were discussed in view of the translocation of materials from host to parasite.