• Journal of Industrial Technology
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• v.29 no.A
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• pp.145-153
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• 2009

In this study, to determine characteristics of compaction and the soil water characteristic curve(SWCC) in decomposed granitic soils, compaction tests and SWCC tests were carried out for samples having various contents of coefficient of uniform($c_u$), By compacting their samples with standard Proctor density test, the effects of binder contents on maximum dry density and optimum moisture content were investigated and compared. Samples compacted with the maximum dry density and the optimum moisture content were tested by means of the SWCC, to determine their SWCC parameters, such as Brooks & Corey(${\lambda}$, ${\Psi}_b$), Van Genuchten (${\alpha}$, n, m), Fredlund & Xing(a, n, m).

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.17-20
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• 2005

In this study, the properties of autogenous shrinkage stress and dry shrinkage stress for high strength concrete using Type I and Type IV cement were discussed. According to experimental results, autogenous shrinkage stress of SN30(the high strength concrete using type I cement) shows values higher than SL30(the high strength concrete using type IVcement). It is observed that the total shrinkage stress of SN30 is higher than that of SL30, because the ratio of autogenous shrinkage stress of the total shrinkage stress is relatively large. Therefore, SL30 is more effective to control or minimize the cracking of the high strength concrete, compared with SN30.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.107-110
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• 2006

The purpose of this study is to suggest a reference data for the development of high workable and normal strength concrete using Polycarboxylate superplasticizer and granulated blast furnace slag as concrete admixtures. So in this study, it is quantitatively evaluated the workability, compressive strength, the heat of hydration and dry shrinkage of high workable concrete on normal compressive strength($21{\sim}27MPa$) for the practical use in construction field. As a result of this study, it is appeared that the performance of high workable and normal strength concrete is superior than that of ready-mixed concrete of the same strength through the B/P tests in the plants.

• Plant Resources
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• v.7 no.3
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• pp.181-186
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• 2004

To find out the optimum fertilizer level for high yielding variety, Paldanghomil, experiment was conducted with 15 compositions of fertilizer levels at the experiment field of forage rye in Sunchon National University from Sep. 1998 to Aug. 1999. The effects of nitrogen fertilizer on plant growth were large significant but increasing rate of application in potassium and phosphate fertilizers above 10kg/10a had negligible effects on plant growth. Raising nitrogen application rate of fertilizers turned out to be 18-10-10kg/l0a of N-P$_2$O$_{5}$-K$_2$O. Content of crude protein was the highest and that of crude fiber such as NDF, ADF, cellulose and lignin were lowest at this rate. Furthermore, IVDMD was high and dry matter yield were the highest at the optimum rate.e.

• Plant Resources
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• v.8 no.2
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• pp.161-166
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• 2005

This study was conducted evaluate the control effect of fungicides on control of Leaf blight, growth characteristics, and dry yield in the cultivation of Job's tears. All fungicides treated had no effect on the growth of Job's tears. The major fungicides were mancozeb Wp, $75\%$, chlorothalonil Wp, $75\%$, dithianon Wp, $43\%$, difenoconazole Wp, $10\%$, benomyl Wp, $50\%$, and propineb Wp, $70\%$. Dry seed yield were increased largely with chlorothalonil Wp, $75\%\;(33g/20\ell)$, fungicide than the other fungicides and control. All fungicides had no injury with standard dosage. On the other hand all fungicides had slight injury in the double dosage level for the Job's tears.

• Plant Resources
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• v.8 no.1
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• pp.67-70
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• 2005

To determine the optimal fertilizer level of wanggol in southeren areas of Korea, Gwangsan ealy local, the highest yielding variety was grown under nine different fertilezer levels. Yield components such as stem length, number of tillers, stem diameter were the highest at the treatments of fertilizer levels, $N-P_{2}O_{5}-K_{2}O=7-2-3$ and 9-2-3 kg/10a plots. Dry cortex and medulla yield were the highest at the treatments of $N-P_{2}O_{5}-K_{2}O=7-2-3$ and 9-2-3 kg/10a fertilizer levels. Judging from the results, an optimum fertilizer level of wanggol seemed to be $N-P_{2}O_{5}-K_{2}O=7-2-3$ and 9-2-3 kg/10a.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.441-444
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• 2006

Extrusion molding concrete panel is cured two times, that is the steam curing at atmospheric pressure and a high-pressure steam curing(autoclaving). Steam curing at atmospheric pressure is done before autoclaving and to acquire the proper strength for treat in process. Though this curing is the important factor on the quality of product and the speed in manufacturing process, it was not evaluated properly so far. Because of ignorance about curing, some engineers even think that the dry curing is better than the steam curing. This study is to investigate the properties of specimen according to variation of curing conditions in the coring chamber such as laboratory scale, pilot plant, and commercial plant. As estimating, in case of steam curing at atmospheric pressure to make extrusion molding concrete panel, moisture curing is better than dry curing and the desirable maximum temperature in curing chamber is about $50^{\circ}C$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.252-253
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• 2013

In this paper, we introduce the insulation of aluminum truss dry installation method for construction for the development of the Angle. Features of the development of anchor bolts have been identified as no risk of fire, and ease of construction, which has the advantage of being the adiabatic efficiency is increased. In future research, to study the angle of the field on the Application of the development for the construction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.28-32
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• 2023

We optimized ultrasound-assisted extraction to improve the extraction efficiency of bioactive compounds from the microalgae Acutodesmus reginae. To optimize this extraction process, we investigated the effects of solvent type, solvent concentration, extraction time, extraction number, and extraction power on the production of lutein, α-carotene, β-carotene, and chlorophylls a, and b. After sequential optimization of these main variables, the maximum amount of each compound was extracted at 30℃ with an ultrasound power of 80 W and using 99.5% methanol. Under these optimum conditions, the amount of lutein, α-carotene, β-carotene, and chlorophylls a, and b, were measured as 10.43, 8.66, 3.76, 15.43, and 6.39 mg/g dry matter respectively.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.1
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• pp.7-14
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• 2015

The aim of this research is suggesting dry processed bottom ash as a new and economical source of lightweight aggregate for mortar and concrete. The dry process of bottom ash is an advance method of water-free and no chloride because only cooled down by double dry conveyer belt systems. Furthermore, because of relatively slow cooling down process helps burning up the remaining carbon in bottom ash. Using this dry process bottom ash, to evaluate the feasibility of using as a lightweight aggregate for mortar and concrete, two-phase of experiments were conducted: 1) improving shape of the bottom ash, and 2) controlling grade of the bottom ash. From the first phase of experiment, additional abrasing process was conducted for round shape bottom ash, hence improved workability and compressive strength was achieved while unit weight was increased comparatively. Based on the better shape of bottom ash, from the second phase, various grades were adopted on cement mortar, standard grade showed the most favorable results on fresh and hardened properties. It is considered that the results of this research contribute on widening sustainable method of using bottom ash based on the dry process and increasing value of bottom ash as a lightweight aggregate for concrete.