• 공업화학
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• 제29권2호
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• pp.168-175
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• 2018

본 논문에서는 대나무 섬유(BF)의 화학처리가 BF 및 폴리프로필렌(PP)/대나무섬유(BF) 복합체의 물성에 미치는 영향을 고찰하기 위해, 알칼리 처리 전후의 BF에 대해 ${\gamma}$-aminopropyltriethoxysilane (APS), ${\gamma}$-glycidoxypropyl-trimethoxysilane (GPS) 그리고 ${\gamma}$-mercaptopropyltrimethoxysilane (MRPS)을 이용하여 실란 상용화제를 처리하였다. BF의 화학처리에 따른 형태학적 특성은 광학현미경(OM)과 주사전자현미경(SEM)을 통해 확인하였으며, 화학 구조의 변화는 FT-IR과 EDS를 통해 확인하였다. 실란처리 시 BF의 열안정성이 증가함을 TGA를 통해 확인하였다. 실란 처리한 PP/BF 복합체의 굴곡강도와 충격특성이 개선되는 것을 만능시험기(UTM)와 충격강도시험기(Izod impact test)를 통해 확인하였고, PP/BF 계면 접착특성이 개선되는 것을 인장시험 후 시편의 파단면을 SEM 사진을 통해 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 추계 학술논문 발표대회
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• pp.41-42
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• 2015

The concrete aggregate generates carbon dioxide in production but its demanding is gradually increased in accordance with the depletion of natural resources. Therefore we evaluated compatibility and basic physical properties of Silicon manganese slag generated in iron production as an applicable concrete aggregate. In our test, the silicon maganese slag shows 2.8g/㎥ of density in 10mm of maximum particle size similar to a natural aggregate, and its absorption rate was 0.3% similar to the electric furnace slag. Unit volume weight and ratio of absolute volume was respectively 2,001㎏/㎥ and 51%. Strength properties of Silicon manganese slag will be evaluated with further studies and experiments.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 추계학술발표대회 논문집
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• pp.154-159
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• 1999

In this paper we present tile results of an experimental investigation on the physical and mechanical properties of carbon fiber grid, polymer mortar, and carbon fiber grid reinforced plain concrete flexural members. In order to repairing and reinforcing damaged and/or deteriorated existing concrete structural members, new materials have been developed and utilized in the construction industries. But the physical and mechanical behaviors of the material are not well understood. To use the material effectively various aspects of the material must be throughly investigated analytically as well as experimentally. In this investigation we found the physical and mechanical properties of carbon fiber grid and polymer mortar which are directly utilized in the repair and reinforcement design of damaged or deteriorated concrete structures. In addition, we also investigate the strengthening effect of carbon fiber grid on the plain concrete flexural test specimens. It was found that the material can be used to repair and strengthen the concrete structures effectively.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.599-605
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• 1999

An experimental investigation was carried out to study the feasibility of using the stabilized sludge, as a backfill and cutoff-water materials for embanckment structures. for stabilizing of sludge, hydrated lime and quick lime was used as additive , and a series of tests was performed on the sludge and the stabilized sludge to examine their physical properties, compaction, compressive strength, hydraulic conducivity and consolication characteristics. From the test results, the physical and mechanical properteis of the stabilized sludge weremore improved as compared with the sludge. Especially from the viewpoint of physical porperty , consolidation or settlement and cutoff-water , quick lime is more effective than the hydraged lime as tabilizatio addtivie. But , viewpoint of compaction and shear strength, hydrated lime is more effective than the quick lime as stabilization additive. As a result of this study, it was founded that the stabilized sludge can be developed the backfill and cutoff-water materials , improved the stabilizing method of sludge.

• Elastomers and Composites
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• 제5권1호
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• pp.69-74
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• 1970

The influence of various calcium carbonate on the physical properties of natural rubber have teen carries out extensive experiments on compounding. Final evaluation was made through various kinds of physical test-tensile strength, modulus, tear strength and hardnees-including particle size. The results are as follows: 1. Generally, tile tensile strength, modulus and tear strength showed the similar tendency in various calcium carbonate compounding. 2. The maximum volume of general using have been obtained with 150 phr calcium carbonate in $NR-CaCO_3$ compounding. 3. The particle size of domestic calcium carbonate showed $1.0\mu-2.6\mu$.

• 한국안전학회지
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• 제18권4호
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• pp.85-91
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• 2003

In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

• 대한치과교정학회지
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• 제48권5호
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• pp.316-325
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• 2018

Objective: The aim of this systematic multiscale analysis was to evaluate the effects of thermoforming on the physical and mechanical properties of thermoplastic materials used to fabricate transparent orthodontic aligners (TOAs). Methods: Specimens were fabricated using four types of thermoplastic materials with different thicknesses under a thermal vacuum. Transparency, water absorption and solubility, surface hardness, and the results of three-point bending and tensile tests were evaluated before and after thermoforming. Data were analyzed using one-way analysis of variance and Student's t-test. Results: After thermoforming, the transparency of Duran and Essix A+ decreased, while the water absorption ability of all materials; the water solubility of Duran, Essix A+, and Essix ACE; and the surface hardness of Duran and Essix A+ increased. The flexure modulus for the 0.5-mm-thick Duran, Essix A+, and eCligner specimens increased, whereas that for the 0.75-/1.0-mm-thick Duran and eClginer specimens decreased. In addition, the elastic modulus increased for the 0.5-mm-thick Essix A+ specimens and decreased for the 0.75-mm-thick Duran and Essix ACE and the 1.0-mm-thick Essix ACE specimens. Conclusions: Our findings suggest that the physical and mechanical properties of thermoplastic materials used for the fabrication of TOAs should be evaluated after thermoforming in order to characterize their properties for clinical application.

• 한국작물학회지
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• 제43권2호
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• pp.83-88
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• 1998

From the evaluation of physical properties such as springiness, gumminess, adhesiveness, chewiness and hardness by the texture analyzer, vegetable soybean lines with green seed-coat were best as compared with those with black, brown, mixed, and yellow seed-coats. A panel test evaluated on the basis of taste, sweetness, chewiness, and total scores also indicated that soybean lines with green seed-coat were the best. The total scores of panel test was decreased in the order of green > yellow> black> brown seed-coat colored soybean. The mean value of sucrose content obtained by HPLC analysis was highest in black seed-coat colored soybean, and followed by green, yellow, and brown soybeans. The highest sucrose content (8.22%) was observed in 180362, a soybean line with green seed-coat. The full-season type soybeans showed much higher sucrose content than summer types which are mainly cultivated on farmer's fields for vegetable purposes. The final 13 lines selected from 300 colored soybeans showed nearly the same panel scores as Miwongreen. However, these lines had a great deal of variation in sucrose content, and much higher readings in texture analysis than Miwongreen, especially in chewiness and hardness which were the most important properties in vegetable soybeans.

• 한국염색가공학회지
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• 제34권4호
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• pp.250-260
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• 2022

In this research, a high-elasticity acrylic emulsion binder with core-shell polymerization and self-crosslinking system is mixed with a flame-retardant water-dispersed polyurethane (PUD) binder. In addition, finite element analysis was conducted through virtual engineering software ANSYS by applying three representative nonlinear material models. The most suitable nonlinear material model was selected after the relative comparison between the actual experimental values and the predicted values of the properties derived from simulations. The selected nonlinear material model is intended to be used as a nonlinear material model for computational simulation analysis that simulates the experimental environment of the vibration test (ASTM E1399) and the actual fire safety test (ASTM E1966). When the mass fraction of thermally expandable graphite was 0.7%, the thermal and physical properties were the best. Among the nonlinear material models, the simulation result of the Ogden model showed the closest value to the actual result.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.17-21
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• 1997

This study was carried out to develop the manufacturing technique of Korean paper(Hanji) and find out new uses of machine-made Hanji produced on a a large scale by paper machine. Six kinds of Hanji were made and laminated with backpaper by acryl-based or vinyl acetate ethylene-based adhesive. Six kinds of wallpapers were made such as WH 1, WH 2-1, WH 2-2, WH 3-1, WH 3-2 and WH 4. Physical properties and quality test on the wallpapers were examined. Physical strength of the wallpapers was better than each strength of the Hanji and backpaper. It might be a roll of adhesive. And so, Production cost of the Hanji could be brought down if the Hanji was made thin to get strength not enough to cut during lamination of two papers(Hanji and backpaper). Hanji wallpapers of WH 3-1 and WH 4 are lower than a standard in sunlight resistance and WH 1 is in properties of opacity. WH 2-1, WH 2-2 and WH 3-2 were better than Korean standard in some quality tests. WH 2-2 and WH 3-2 were superior to other wallpapers as a whole. About, twenty kinds of wallpapers with surface treatment, are now being produced on the basis of these two types of wallpapers.