• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.1
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• pp.47-53
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• 2011

From recent research, it has revealed that Electroacitve polymer(EAP) has a physical limitation. Carbon nanotube(CNT) is known as the promising material which has excellent electro-mechanical characteristics and is mostly defect-free. It is expected that a successful synthesis of CNT and Nafion known as a primary material for IPMC would make a great improvement on its electro-mechanic feature. In this paper, we suggest the method of synthesis of CNT with Nafion which improves electro-mechanical characteristic. Using mechanical dispersion with Nafion and Isopropyl Alcohol(IPA), we disperse Single-walled carbon nanotubes(SWCNT). For a uniformly layer of CNT, we used a spray gun on a hot plate by a simplified method. In the result, we fabricated a disperse SWCNT/Nafion composite uniformly.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.252-257
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• 1999

The distinguished geological characteristic of Taegu area is consist of anisotropic shale or sedimentary rock. Therefore if rocks are used for construction, it would've some difficulties of reuse showing the aspect of resource engineering. We made physical and mechanic properties for rock discrimination and then whether it had utilization worth or not. So we studied the engineering propriety through the aggregate tests based on rock's in laboratory. The last passed aggregate were D, E and B1 at KS and the rest couldn't use the place where weather phenomenon is caprice. This sis for base-line data of aggregate development research before the porpriety investigation for aggreagte of excavated rock in Taegu area.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.5
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• pp.131-136
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• 2011

Many researchers are recently studying about Electroactive polymer(EAP). But it has a physical limitation, because of property of material. Carbon nanotube(CNT) is known as the promising material which has excellent electro-mechanical characteristics and is mostly defect-free. It is expected that a successful synthesis of CNT and Nafion known as a primary material for IPMC would make a great improvement on its electro-mechanic feature. This study focuses on the method of synthesis of CNT with Nafion which improves electro-mechanical characteristic. To come up with mechanical dispersion with Nafion and Isopropyl Alcohol(IPA), we dispersed Single-walled carbon nanotubes(SWCNTs). For a uniformly layer of CNT, we used a spray gun on a hot plate by a simplified method. We fabricated a disperse SWCNT/Nafion composite uniformly. Through the use of the E-beam evaporator to form an uniform electrode layer, we consummated the IPMC actuator. This result shows improving 1.5 times mechanical properties about driving force in IPMC.

• The Journal of Engineering Geology
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• v.14 no.2
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• pp.199-210
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• 2004

In this study, the physical and mechanical properties of the weathered shale soils distributed in the Hwasun area have been measured in the laboratory. The physical and mechanical properties of the weathered shale soils in the study area as follows: the specific gravity is 2.66 to 2.68, the liquid limit is 36.39 to 36.92(%), the plastic limit is 18.53 to 19.48(%), the plasticity index is 17.44 to 17.86 and soil classification is CL. The maximum dry unit weight and optimum moisture content as calculated by compaction test is 22.5 to 23% and 1.58 to $1.61t/\textrm{m}^3$, respectively. The result of direct shear testing show that cohesion in saturated and unsaturated conditions increases according to the increase of dry unit weight. Internal friction angle in an unsaturated condition increases with an increase of dry unit weight, but in a saturated condition, it increases after decreasing. When compares with engineering characteristics of tile weathered shale soils in the Daegu area (Kim et al., 1995), specific gravity is found to be similar, but the liquid and plastic limit of soil samples in this study area is slightly higher than those of soil samples in the Daegu area.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2003.10a
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• pp.134-138
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• 2003

The purpose of this paper is to recycle the fly ash to the valuable resources and settle environment problems which was caused by the fly ash produced from the thermal power plant. Making the fly ash-cement matrix reused fly ash in large quantities, we looked into minutely the physical properties - the elastic modulus, the compressive strength - to increase the usefulness as the building materials for the structure widely. In this paper, the variables are the water-binder(39, 42, 45%), the fine aggregate ratio(37, 41, 45%). Because the fracture energy is influenced by the strength, it is showed to decrease with the increase of W/B and S/a. Besides, we will be able to know that basic properties of the fly ash-cement matrix are similar to that of concrete. But, it is needed to carry out durability experiment on the drying shrinkage, creep, freezing and thawing test to use structural materials.

• Journal of Biosystems Engineering
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• v.35 no.4
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• pp.244-249
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• 2010

This study was conducted to define the optimal Lycium chinense miller washing method for developing the Lycium chinense cleaner and we analyzed the Lycium chinense miller washing characteristics for removing pesticides and microorganism according to washing methods; habitual washing method, air bubble washing method and nozzle spray washing method. The results were summarized as follows; 1. In case of measuring physical properties according to the varieties, maximum yield strength of Hokwang was 2.562 kgf, minimum yield strength of Hokwang was 0.269 kgf and average yield strength was about 1 kgf. 2. In case of measuring change of bacteria according to washing methods, the number of bacteria of non-washing method was more than the number of bacteria of habitual washing method or mechanical washing method and the number of nozzle spray washing method was least. 3. Ahjoksiseuteurobin of 0.218 ppm was detected in the untreated sample, 0.051 ppm was detected in the habitual washing method, 0.047 ppm was detected in the air bubble washing method and 0.034 ppm was detected in nozzle spray washing method. Every amount detected were less than 2 ppm that is reference value and the detected amount was least in case of nozzle spay cleaning method. Cypermethrin of 0.772 ppm was detected in the non-cleaned sample, 0.089ppm was detected in habitual washing method, 0.26 ppm was detected in the air bubble washing method and 0.292 ppm was detected in the nozzle spray washing method. Every detected amount of Cypermethrin were less than 5 ppm that is reference value and the detected amount was least in case of habitual washing method.