• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.214-214
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• 2006

The huge amounts of wastes were produced nowadays. Among the solid waste stream, the waste plastic portion is about 20 % in weight, over 50 % in volume. But the most of waste plastics were incinerated or land filled. Only a bit of waste plastics were recycled and reused. On the view point of current energy crisis, this will be an extravagance of beneficial resource. So we should consider the waste plastics as a beneficial raw material. Also need to develop the field of reusing and recycling of post-consumed plastic. In this context, present paper describes the methodology for enhancing or improving the specific properties by way of using inorganic filler waste. Also develop the product from these post-consumed plastic.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.825-830
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• 1999

The purpose of this study is to improve overall performance of prefoamed lightweight cellular concrete for On-Dol system floor. This study includes 4 sections as follows. \circled1 Analysis of the structural characteristics of On-Dol System focusing on the lightweight cellular concrete insulation layer. \circled2 Establishment of the mixing design equations. \circled3 Development of some admixtures used with foaming agent. \circled4 Improvement of the equipment for onsite production. This study has proven that, compared with the current existing one, the newly developed lightweight cellular concrete has been reduced the usage of cement by 20% and the cracks caused by cement drying shrinkage up to 80% but has shown the increased compression strength by 20% at 7 days curing period. The volume contraction of freshly prepared cellular concrete by the loss of foam was hardly found in newly developed lightweight cellular concrete.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1643-1647
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• 2000

The intake noise of an automobile induced by firing of an engine accompanies acoustic resonances of ducts of an intake system. Conventionally, the adoption of the Helmholtz type resonator was one of possible ways to eliminate the booming noise due to acoustic resonances of air ducts. Although the Helmholtz type resonator is convenient to attenuate the intake noise of an automobile, the usage of the Helmholtz type resonator requires cost increase or big engine room space. Therefore, reduction of the number of the resonators or the volume of the resonators is essential to increase the value of an automobile. To meet these requirements, other types of resonator are suggested instead of the Helmholtz type resonator. The effectiveness of the suggested resonators is compared considering noise reduction ability, effect to the engine performance and size of each resonator.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.386-389
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• 2002

It may be necessary to apply a daily fever to operate the municipal solid waste landfill. The daily cover helps to control nuisance factors such as the escape of odors, dusts and airborne emissions, and can control the population of disease vectors. Also it may be reduce the infiltration of rain, decreasing the generation of leachate and the potential for surface water and groundwater contamination. Because of its usual availability and traditional usage as the municipal solid waste landfill, soil remains as the most common daily cover material. However, soil tends to reduce the volume of dumping waste c;3pacity in the landfill, it also reduces a period of using in the landfill. Therefore, it is necessary to research about Alternative Daily Cover Materials (ADCMs) because of the limitation of landfill sites. Recently, The types of ADCMs are classified into geosynthetics, forms, spray-ons, indigenous materials. In this study, the authors have tested the spray type of Alternative Daily Cover(ADC) using by flyash, alum with cement. The development. of ADCMs will be highly effective in terms of prolongation using landfill.

• Progress in Superconductivity and Cryogenics
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• v.6 no.4
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• pp.51-54
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• 2004

A 1 MV A single phase high temperature superconducting (HTS) transformer was manufactured. In order to reduce AC loss generated in the HTS winding, winding was concentrically arranged. Operation temperature is set at 65K to increase the critical current and reduce the amount of HTS tape usage and the volume. The cryogenic system which consists of main cryostat with the windings and secondary cryostat with 2 GM coolers and cryopump on top and heat exchanger inside is also designed and the cooling performance is simulated with Fluent. Temperature distribution of the windings is investigated whether the windings are kept under designed operation temperature.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.2
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• pp.129-132
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• 2011

This paper presents small hydrogen regulator for the mobile fuel cell. Mobile fuel cell is generally classified into open-end type and dead-end type. In the open-end type, flow rate of hydrogen is constantly controlled, while pressure of hydrogen is constantly maintained in the dead-end type. Considering the efficiency and stability of the fuel usage, dead-end type is more suitable with mobile fuel cell. Mobile fuel cell operated by dead-end mode requires hydrogen regulator which controls the hydrogen pressure from 0.1bar to 0.5bar within 3% error. In this paper, small hydrogen regulator (volume of 2.6cc) was fabricated by stainless steel. Regulation characteristics was experimentally evaluated.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.173-174
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• 2003

Activated carbons (ACs) are widely used in adsorption for the removal of gaseous and aqueous pollutants[1,2]. The microbicidal property of ACs is also very important, in order to decrease the risk of water and air contamination with microorganisms. For this purpose, ACs have impregnated with silver or with metallic oxides[2]. However, in the case of Ag supported ACs prepared by impregnation, there are some problem, such as, heat-treatment, highly decrease in specific surface area and pore volume by deposited Ag, and rapidly elution of Ag at the initial stage of usage[3]. (omitted)

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.316-324
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• 2001

To prepare an acrylic type pressure-sensitive adhesive, quarternary polymers were synthesized from butyl acrylate (BA), 2-ethyl hexyl acrylate (2-EHA), methyl methacrylate (MMA), and 2-hydroxy ethyl methacrylate (2-HEMA). The quarternary polymers were identified by FT-IR and Molecular weight was measured by Gel Pearmeation Chromatography. Also, viscosity, solid content and peel strength were examined. The peel strength was 160 $g_{f}/25$ mm when the volume ratio of feed monomer to solvent was 1.3:1, and the ratio was relevant to commercial usage. The pot life of adhesive was 30 sec at the 50 m/min of heat treatment rate at, and it indicated that the minimum drying time was 30 sec. In weathering resistance test, peel strength of $160{\sim}180$ $g_{f}/25$ mm after 1000 h, with no residual remains on the adhesive surface.

• Advances in Energy Research
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• v.3 no.1
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• pp.31-43
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• 2015

This paper compares the performance of JP-8(Jet Propellant) fuel and liquefied petroleum gas (LPG) and natural gas in the F110 GE100 jet engine. The cost of natural gas usage in gas turbine engines is lower than JP-8 and LPG. LPG cost is more than JP-8. LPG volume is bigger than JP-8 in the same flight conditions. Fuel tank should be cryogenic for using natural gas in the aircraft. Cost and weight of the cryogenic tanks are bigger. Cryogenic tanks decrease the move capability of the aircraft. The use of jet propellant (JP) is the best in available application for F110 GE 100 jet engine.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.71-77
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• 2007

Advance of neuroimaging technique has greatly influenced recent brain research field. Among various neuroimaging modalities, positron emission tomography has played a key role in molecular neuroimaging though functional MRI has taken over its role in the cognitive neuroscience. As the analysis technique for PET data is more sophisticated, the complexity of the method is more increasing. Despite the wide usage of the neuroimaging techniques, the assumption and limitation of procedures have not often been dealt with for the clinician and researchers, which might be critical for reliability and interpretation of the results. In the current paper, steps of voxel-based statistical analysis of PET including preprocessing, intensity normalization, spatial normalization, and partial volume correction will be revisited in terms of the principles and limitations. Additionally, new image analysis techniques such as surface-based PET analysis, correlational analysis and multimodal imaging by combining PET and DTI, PET and TMS or EEG will also be discussed.