• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.169-173
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• 1998

Three dimensional database of building use in Central Obihiro City was created and displayed using three dimensional graphics and quicktime movies. Then intra structure of Central Obihiro City was analyzed based on this database using GIS and the results were also displayed using three dimensional graphics and quicklime movies.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.275-282
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• 2020

As pesticide safety was extended to agricultural environments and Positive List System was carried out, Pesticide safety management in soils has become even more important. To improve pesticide safety in soils needs the degradation technology of the residues in soils and reduce plant uptake of pesticides. In this study, biochars and quicklime as the degradation methods of pesticides (azoxystrboin, procymidone and tricyclazole) were used to identify the reduction effects. The experimental methods were putting biochars and quicklimes (0, 0.5, 1.0, 2.0% per 15 cm soil weight) in soils and analyzing the pesticide residues at 0, 10, 20, 35, 50 day. To identify the reduction effects of uptake from soil to korean cabbages (roots, leave, stems) by biochar treatment, the residues in samples were analyzed. As a results, azoxystrobin (36-96%), procymidone (40-117%) and tricyclazole (26-83%) were reduced in soils when treated with 2.0% quicklime (p<0.05). There were no reduction effect in soils when treated with 1.0% or less biochar. However, the amounts of residues translocated to roots (0.11-1.62 mg/kg), leave (0.05-0.29 mg/kg), stems (0.06-0.1 mg/kg) were reduced treated with 2.0% biochar treatments. The biochar and quicklime can be applicable to agricultural field to improve pesticide safety in soils.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.279-283
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• 2000

Lime is one of the world's most useful chemicals and manufactured in various types of kilns, using various fuels. Quicklimes vary in reactivity with water due to variations in the time and temperature calcining process and type of kiln used. Careful attention and control of time and temperature in the calcining process is necessary to insure a highly reactive lime. Excess time and temperature will cause the lime to be over burned. The highest reactivity of quicklime is obtained by calcination of limestone in the particle size of 0.1cm~2cm, calcination temperature of $1000^{\circ}C$, calcination time 90min. It was found by the scanning electron microscopes that pores of quick lime is reducted if the soft burned quick lime is heated continually.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.227-232
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• 1999

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture for the effective use of surplus soils, and the shear strength with curing time was estimated at the content of lime. The effect of strength improvement has been established through the change of lime content with chlorides and sulfates from the samples taken at Samsan region, Ulsan. The test results indicated that the presence of calcium sulphate encouraged the efficiency of lime stabilization, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.55-62
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• 2000

In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture with fly ash and rice husk ash for the effective use of surplus soils, and the shear strength with curing time was estimated at lime 10 percent with the change of fly ash and rice husk ash content. The effect of strength improvement has been established through the change of fly ash and rice husk ash content from the samples taken at Samsan region, Ulsan. The test results indicated that the presence of lime with fly ash and rice husk ash encouraged the stabilization efficiency of lime with fly ash and rice husk ash, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.37-42
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• 2001

생석회말뚝공법은 연약점토에 대한 유용한 지반개량공법으로서 그 개량효과는 매우 빨리 나타난다. 본 연구에서는 생석회말뚝 타설 면적비에 따라 연약점토지반의 함수비나 전단강도 등의 특성이 어떻게 변화하는가를 규명하고자 하였다. 이를 위하여 철제상자에 연약점토로 모형지반을 조성하고 소요 면적비로 생석회말뚝을 타설한 후 적당한 시간간격을 두고 함수비와 전단강도를 측정하는 실내 모형시험을 수행하였다. 그 결과 면적비가 증가함에 따라 함수비의 감소량과 전단강도의 증가량은 커지지만 면적비가 약 10%를 초과하면 별 차이를 보이지 않으며 같은 면적비에서 생석회말뚝의 지름이 작고 간격이 좁으면 함수비의 감소량과 전단강도의 증가량은 더 크다는 것을 규명하였다. 또한 같은 양을 사용했다면 생석회말뚝공법보다 생석회혼합공법을 적용한 흙의 전단강도 증가량이 더 크다는 것을 알 수 있었다.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.2
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• pp.21-28
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• 2019

Handmade hydrated lime has been used for preservation and repair of architectural heritage in Korea. However, the effect of the amount of water used for slaking quicklime on the physical and chemical properties of the hydrated lime, which is the result of the slaking process, has not been clearly understood. In this study, particle size distribution, chemical composition and crystalline phases of the hydrated lime are investigated by varying the amount of water used for the slaking. In addition, temperature history during the slaking process is examined. For this, various experiments, such as laser diffraction analysis, X-ray fluorescence, X-ray diffraction, thermogravimetric analysis, and temperature recording using a thermocouple, were performed. When the quicklime came into contact with water, its temperature reached $100^{\circ}C$ within 10 min due to sudden exothermic reaction of calcium oxide, and this temperature was maintained for about 30 min. The water to lime ratio influenced the cooling rate during the slaking process; that is, the more water was used, the longer it took to reach an ambient temperature. The amount of water for the slaking did not have a noticeable effect on the contents of major components of the hydrated lime such as calcium hydroxide and calcium carbonate, but when slaked with more amount of water, average particle size of the lime tended to decrease. The experimental results in this study can be used as references for developing guidelines on the safety or appropriate amount of water in the lime slaking process.

• Journal of Environmental Science International
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• v.10 no.4
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• pp.275-280
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• 2001

In an attempt to evaluate the possibility of producing an organic fertilizer using sediments from coastal farming areas, the chemical composition, bacteriological quality and heavy metals in the sediments alkalized by conditions : a 1:4 mixture of dry sediment to food wastes and the addition of 30% quicklime to the mixture. According to the classification standard for compost constituent by Higgins, all composts had a low or intermediate grade in T-N and $K_2O$ content, a low grade in $P_2O_5$ and a high grade in CaO and MgO content. Stabilization by quicklime and magnesium hydroxide is likely to inhibit th bacterial decomposition of organic matter and the actigity of pathogenic organic. Raising the pH of stabilized sediment to 12 for 2 hours(PSRP criteria of EPA) allowed 99.99% of the coliform group, fecal group and viable cell count to be reduced. the results suggested that the crude fertilizer produced by alkaline stabilization method was innoxious and thereby the sediments from coastal farming areas could be used as organic fertilizer.

• Journal of the Korean Ceramic Society
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• v.51 no.2
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• pp.115-120
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• 2014

Quicklime(CaO) is generally obtained through the calcination of limestone, the main component of which is calcium carbonate($CaCO_3$). Quicklime generates high-temperature heat when reacting with water, forming slaked lime($Ca(OH)_2$). The industrial sectors for limestone are determined by the hydraulic activity of slaked lime, which is obtained by measuring temperature changes during the hydration reaction. Accordingly, this study examined the different crystallographic characteristics of limestone as affected by the geological origins of the regions where the limestones were produced, and how these characteristics affected hydraulic activity. Six limestone samples were collected from the Jecheon and Cheongsong areas and the hydraulic activities were measured in accordance with KS E 3077. The results indicate that limestone produced in the Cheongsong area, recrystallized through metamorphism caused by hydrothermal alteration, hada larger grain size of calcite than that of the Jecheon area, and displays a tendency of changing to marble. Limestone from the Cheonsong area showed more radical reaction in the early stage of hydration compared to that ofthe Jecheon area. In addition, it was revealed that limestone having more impurities like $SiO_2$ have lower hydraulic activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.508-513
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• 2000

In an attempt to evaluate the fertilizer of sediments obtained from coastal farming areas, chemical composition, bacteriological quality and heavy metals in the sediments alkalized by quicklime and magnesium hydroxide were analyzed. The optimum conditions of alkalization were also measured. A perfect reaction was possible by the addition of quicklime of $30{\%}$ at the rate of $25{\%}$ of sediment and $100{\%}$ of livestock wastes. According to the classification standard for compost constituent by Higgins, all composts had the intermediate or high grade in $T-N, K_2O,\;CaO\;and\;MgO$, but below the low grade in $P_2O_5$, Stabilization by quicklime and magnesium hydroxide has been known to inhibit bacterial decomposition of organic matter and activity of pathogenic organisms. In this study, raising pH of stabilized sediments to 12 for 2 hours (PSRP rriteria of EPA) allowed $99.9{\%}$ of coliform group, fecal group and viable cell count to be reduced. As a result, sediments of coastal farming areas are likely to be used to produce the organic fertilizer by alkaline stabilization.