• Resources Recycling
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• v.12 no.2
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• pp.28-35
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• 2003

The powder utilization is the one of the best recycling methods for the waste tires. However, economic problem still exist. In order to overcome an economic problem the ground rubber particles are surface modified, which induced to the rubber particles that have good mechanical properties and higher compatibility. In this study, we investigated ultrasonic treatment and reduced rubber particle size. Results showed that sulfur cross-linkage network of the waste rubber is changed by the ultrasonic treatment.

• Economic and Environmental Geology
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• v.52 no.6
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• pp.617-626
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• 2019

In this study, we investigated the petrographic characteristics and physical property of the Rock-carved Seated Buddha at Bugmireugam hermitage of Daeheungsa temple in Haenam. The Buddha Statue was carved on micrographic granite, and the rock was composed of the fine quartz encircled by orthoclase. The results of diagnosis for deterioration evaluation have shown a highly damage rate of black contaminants (8.4%) and crack index (6.6). The ultrasonic velocity have detected SW (slightly weathered) grade of weathering coefficient (mean 0.18). Various weathering factor on the surface of the Buddha Statue was affected by precious shelter, and physical property with ultrasonic was directly influenced by the structural characteristics and fissure of host rock.

• Elastomers and Composites
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• v.38 no.2
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• pp.128-138
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• 2003

It goes to be serious with environmental pollution because of great number of waste tires scrapped each you. That is why there are lots of studies for efficient recycle. We tried to reduce particle size of the waste tire powder using a new technology of self-designed grinding machine (SDGM) and ultrasonic treatment. The purpose of this study is to improve the physical properties of reduced waste tire powder. We investigated the fine powder by particle size distribution(PSD) analysis. And also we examined the physical and mechanical properties and cross-link density at various particle sire. Also we carried out morphological studies after making the products by SEM.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.1-7
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• 2015

Purpose: For optimizing properties of final glasses frame, the aim of this study is to examine the correlation of processing conditions and properties of cellulose acetate (CA) sheets through the investigation of properties of CA sheets prepared under processing steps. Methods: The properties of CA sheets were investigated in terms of different glasses frame processing conditions, bending process, barrel process, and ultrasonic cleaning process. CA sheets prepared through the sequential processing were examined by various analysis: gloss, mechanical properties, thermal properties. Results: After barrel process, hardness and tensile strength of CA sheet were increased. However, bending strength and impact strength were decreased. It is suggested the CA sheet had became rather stiff state (brittle). Also, in degradation temperature region of plasticizer, about 3% of reduction in plasticizer weight was confirmed upon TGA analysis. Conclusions: Glasses frame process, especially in the barrel process have a profound influence on the properties of CA sheet owing to reduction of total amount of plasticizer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.375-376
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• 2008

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.07a
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• pp.462-468
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• 2003

최근 전자산업의 발달로 첨단기술의 농업적 응용에 필요한 각종 센서가 개발되고 있어 이를 이용한 농산물의 각종 품질을 비 파괴적으로 측정할 수 있는 연구가 활발히 진행되고 있다. 여러 농산물 중과실의 경도와 같은 물성 인자는 그 중요성에도 불구하고 비 파괴적으로 측정할 수 있는 기술이 개발되고 있지 않고 있다. 레이저 분광법의 경우 표면의 광 산란현상을 이용하여 경도를 비교적 정확하게 측정할 수 있으나 아직까지는 시스템의 가격이 고가이며 사용에 많은 제약이 따르며 근적외선 분광분석법을 이용한 경도 측정은 현재까지 그 정확도가 낮다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.539-540
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• 2009

• 한국가스학회:학술대회논문집
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• 2005.05a
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• pp.234-234
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• 2005

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.179-182
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• 2006

• Journal of Conservation Science
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• v.32 no.3
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• pp.425-436
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• 2016

The Yakhyeon catholic church (Historic Site No. 252 in Korea) that was constructed in 1892 has been the first western brick structure to ever have existed and one of the most important historical materials in the Korean modern architecture. After a fire had broken out at the catholic church in 1998, the stained glass on the back wall, the slab glass (dalle de verre) introduced by Lee Nam Guy in 1974, was repaired in 1999 because of singe scorch and water leakage. An analysis of the coloration elements showed that yellow, red and green included Zn, K and Cd, respectively. The glass of red contained Se, dark green contained Mn and Cr, and blue contained Pb and S. According to material analysis, the masonry joint was identified dolomite ($CaMg(CO_3)_2$) and calcite ($CaCO_3$), which was observed plate, columnar, rhombic and square of crystalline particles. Meanwhile, ultrasonic velocity in the stained glass recorded low speed in the middle and lower right of the window (an average of 4,130 m/s). And the joint was measured the lowest physical properties of the top left and middle of the window (an average of 2,053 m/s). This study have showed that extensive physical damage was founded to the left and middle rather than the right side. In this respect, more research in needed to conserve the correlation between color and physical properties.