• Journal of Industrial Technology
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• v.15
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• pp.175-185
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• 1995

Under the new environmental regulations announced by the government, utilities will have to cut their sulfur dioxide emissions by 60% from 1991 levels by the year of 1999. Sulfur dioxide emissions can be reduced prior to combustion by physical, chemical or biological coal cleaning. The new technology of high gradient magnetic separation (HGMS) offers the potential of economic separatoins of a variety of fine, weakly magnetic minerals including inorganic sulfur and many ash-forming minerals from coals. In the present paper, magnetic separation tests have been conducted on Korean anthracite and high-sulfur Chinese coal to investigate the feasibility of these techniques for reducing sulfur content from coals. In wet magnetic separation, the studied operating parameters include particle size, pH, matrix types, feed solids content, feed rate, number of cleaning stages and etc. The results shows that for wet separation, 60~70% of total sulfur was removed from coals with over 80% combustible recovery, on the other hand, for dry separation, 47.6% of total sulfur was removed from coals with 75% recovery.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.7 s.178
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• pp.1748-1752
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• 2000

In this paper, the measurement technique of cutting temperatures of shear zone using implanted thermocouples is proposed in ball end milling. K-type thermocouple implanted in the hole of workpieces is directly cut in order to measure temperatures of the shear zone in cutting process. Experiments are performed for a nickel based superalloy(Inconel 718) using a ball nose end mill. The results show that the cutting temperature in shear zone is about 3200C at the cutting speed of 90m/min with dry.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.62-69
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• 2007

This study has been carried out to estimate aboveground carbon contents in an average 30-years-old Betula platyphylla and 32-years-old Juglans mandshurica stands in Chungju, Chungbuk Province. Nine sample trees were cut in each forest and soil samples were collected. Carbon concentration in stemwood, stembark, branch, and foliage were ranged from 54.6% to 57.0% in Betula platyphylla and 53.5% to 56.9% in Juglans mandshurica stands. Aboveground carbon contents was estimated by the equation model logWt=A+BlogD where Wt is oven-dry weight in kg and D is DBH in cm. Total aboveground carbon contents was 34.31t/ha in Betula platyphylla stand and 21.10t/ha in Juglans mandshurica stand. Aboveground net primary carbon production was estimated at 2.31t/ha/yr in Betula platyphylla stand and 2.03t/ha/yr in Juglans mandshurica stand.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.59-64
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• 2017

The general manufacturing problem can be described as the achievement of a predefined product quality with given equipment, cost and time constraints. Unfortunately, for some quality characteristics of a product such as surface roughness it is hard to ensure that these requirements will be met. Stainless steels STS 304 is frequently used as shaft materials in small fiber reinforced polymer(FRP) fishing boats. In this work, the dry turning parameters of STS 304 are optimized by using Taguchi method. The experiments were conducted at three different cutting speeds with three different feed and three different depth of cut. The cutting parameters are optimized using signal to noise ratio and the analysis of variance. The effects of cutting speed and feed on surface roughness was analyzed. The results revealed that the spindle speed is the more significant parameter influencing the surface roughness.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1599-1602
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• 1994

Recently, failure of COS(cut out switch) due to contamination has been increased. This paper is on the development of the contamination COS. 1 We designed a porcelain insulator of alternate shed for anti-contamination COS. 2 The COS was coated with HVIC(silicone) to improve resistivity to contamination. 3 The FOV characteristics of COS were examined to obtain dry FOV, wet FOV and contamination FOV.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1369-1375
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• 2006

This study analyzes stability and the reason of slope failure about cut slope on stony mountain in Acheondong, Guri and suggests the reasonal reinforce method. Based on the results of the subsurface exploration, laboratory tests, and the numerical analysis of finite element method, the potentials of plane and wedge failure are highly estimated. The safety factor was 1.2 under dry and 1.06 wet condition. The most proper reinforce method to raise the safety factor more than 1.5 was the way to control displacement by using step retaining wall, earth anchor, wire mesh, and rock anchor.

• Current Research on Agriculture and Life Sciences
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• v.31 no.1
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• pp.56-60
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• 2013

This research was carried out to produce rainbow-colored roses from white cut rose, Rosa hybrida 'Denice', to meet customers' desire of having various colors of roses. The higher temperature of dyeing solution used, the faster coloring time surveyed. In high temperature, the flowering speed of cut flower accelerated and after treating more than 4 hours, the edges of flowers became too dark or dry. In the condition of concentration of dyeing solution, $11g{\cdot}L^{-1}$ dyed faster than $7.5g{\cdot}L^{-1}$, however, no differences between $15g{\cdot}L^{-1}$ and $11g{\cdot}L^{-1}$ have observed. It looked fast coloration at the stage of early blooming, but all three different petal opening stages need similar time to get even coloration from outer to inner petals. For the consideration of commercial value, flowers with 3-4 petals opened are better quality than flowers with less petals opened. It was possible to make rainbow-colored rose by dipping 'Denice' with 3 primary color combination, Hot Pink, True Blue, and Yellow dyes, at the best result conditions of $20^{\circ}C$ solution temperature, 3-4 petals opening stage, 11g/L concentration of dye solution and 3 hours dipping, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.258-263
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• 1991

There are ten NLCF's recommended sorghum-sudangrass hybrids(Sorghum bicolor (L.) Moench), but they have not been evaluated under same environmental conditions. Therefore, a field experiment was conducted to campare forage yield and quality of the NLCF's recommended cultivars of sorghum-sudangrass hybrids at the experimental forage field, College of Agriculture, SNU, Suweon over two years. Among the ten cultivars used, G83F and NC+855 were classified as early maturing cultivars. Pioneer 988 and Sordan 79 were more resistant to leaf blight than the other hybrids. Jumbo, Sordan 79 and SX-17 were susceptible to lodging. No significant differences in dry matter yield were found among the cultivars used, but the dry matter yields of Pioneer 988, TE-Haygrazer and G83F were slightly higher than the other hybrids in 1989 and those of NC+855 and Pioneer 988 were higher in 1990. There were no marked cultivar differences in CP, ADF, NDF and RFV at the first, second and third cuts in 1990, but the ADF, NDF and RFV of sorghum-sudangrass hybrids at the third cut showed more higher than those of the first and second cut forage. In conclusion, there are no forage yield differences among the ten NLCF's recommended sorghum-sudangrass hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.116-120
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• 1991

Silage productivity of two sorghum hybrids. Pioneer(P) 931 and P 956, and green fodder productivity of a sorghum-sudangrass hybrid, P 988, were tested at four levels of seeding rates (1, 2, 3, and 4 kg/lOa). The 1st-cut of sorghum hybrids of P 931 and P 956 was made at milk ripe stage for silage on July 22 and 31, respectively and regrowth was harvested on Oct. 13. The 1st-and 2nd-cut of a sorghum-sudangrass hybrid were made at flag leaf emerging stage for green fodder on July 26 and Aug. 16 and 3rd-cut was harvested on Oct. 13. The results obtained are summarized as follows:1. Growth stage, culm length or plant height, and percent dry matter (DM) were similar among the seeding rates. Percent DM of sorghum hybrids ranged 26.9-31.2% regardless hybrids and t ~ m e of harvest. However, in the sorghum-sudangrass hybrid percent DM of the 1st-cut. 2nd-cut, and 3rd-cut ranged 10.0-10.7% 18.2-19.97% and 24.6-27.8% respectively.2. In sorghum hybrids crude(C) fiber content of P 931 was higher, but nitrogen free extract (NFE) was lower compared with those of P 956 and C. protein and C. fat were similar between two hybrids. However, C. protein and C. ash of sorghum hybrids were lower, but C. fiber and NFE were higher compared with those of a sorghum-sudangrass hybrid and C. fat was similar between two crops.3. Total DM yield was greater in the order of P 931>P 956>P 988. The optimum seeding rate for both silage yield of sorghum hybrids and green fodder of a sorghum-sudangrass hybrid was 2-4 kg/lOa. However, yield of the 1st-cut tended to increase as seeding rate increased.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.309-316
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• 2008

Mycelium of Ophiostoma quercus albino strain cultured in liquid culture media was harvested, lyophilized, and stored for examining biocontrol efficacy against wood discoloration by staining fungi in the laboratory and field conditions. Dry weight of mycelium grown in brown sugar yeast extract broth(BYB) showed 3.8 times higher than that grown in potato dextrose broth(PDB). The optimum culture period in BYB was 4 weeks. In vitality test of the albino strain, the lyophilized mycelium stored in liquid nitrogen($-196^{\circ}C$) or in a refrigerator($4^{\circ}C$) kept the vitality until 13 months after storage; however, the mycelium stored at room temperature lost the vitality completely after 13 months. The mycelium stored in liquid nitrogen or in a refrigerator protected wood chips from the discoloration by pretreating mycelial suspension on pine wood chips. The mycelium stored at room temperature for 7 months also showed complete protection. These results suggest that the lyophilized mycelium have a biocontrol efficacy only if it keeps the least vitality. In the field conditions, both albino strain and $Woodguard^{(R)}$(commercial chemical protectant) showed significant differences(p=0.05) in discoloration rate as compared to the non-treated control when these were treated on the wood logs of Pinus rigida. The albino strain showed better protection than $Woodguard^{(R)}$. Isolation frequency of blue stain fungi from the chips of wood logs treated with the albino strain was 0% at three months after treatment, while that treated with $Woodguard^{(R)}$ was 76.7%. In another experiment, pre-treatment of mycelial suspension on the cut surface of wood logs also showed significant protection from wood discoloration. Spraying of both albino strain on the cut surface and insecticides on the bark also showed relatively good control effects as compared to insecticide alone on the bark or nontreated control.