• 한국식품조리과학회지
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• 제9권4호
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• pp.289-292
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• 1993

당알코올의 대체 감미료로서의 유용성을 검토하기 위한 목적으로 LMP jelly들을 제조하여 품질 특성을 비교하였다. 관능검사 결과 LMP jelly의 감미도는 설탕의 50％를 maltitol로 대치하였을때 현저하게 감소하였고, 반면 같은 50％를 3종류의 당알코올로 혼합 사용한 경우에는 제조시 당알코올의 대체 가능성을 높음을 시사하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.298-299
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• 2008

The materials are measured and analyzed by the UTM combined with a contact type extensometer so as to analyze the characteristics such as strain-stress curve. However, the JIG and Fixture utilized in the UTM according to the standard [ASTM] can not only scratch the specimens but also have a serious distort on test result by the weight of the ZIG itself. In this paper we propose a moncular vision based visual extensometer [VE] securing the measuring accuracy using a new cross correlation in detecting the two feature points previously marked on the specimen from two successive images, and verify the usefulness of this VE through a real experiment on the UTM.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.270-273
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• 2009

A comb-like copolymer consisting of a poly(vinylidene fluoride-co-chlorotrifluoro-ethylene) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. P(VDF-co-CTFE)-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance (1H-NMR), FT-IR spectroscopy, and transmission electron microscopy (TEM). This comb-like polymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA and the -COOH groups of IDA. Upon doping with phosphoric acid ($H_3PO_4$) to form imidazole-$H_3PO_4$ complexes, the proton conductivity of the membranes continuously increased with increasing $H_3PO_4$ content. A maximum proton conductivity of 0.015 S/cm was achieved at $120^{\circ}C$ under anhydrous conditions. In addition, these P(VDF-co-CTFE)-g-PHEA/IDA/$H_3PO_4$ membranes exhibited good mechanical properties (765 MPa of Young's modulus), and high thermal stability up to $250^{\circ}C$, as determined by a universal testing machine (UTM) and thermal gravimetric analysis (TGA), respectively.

• 한국염색가공학회지
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• 제31권4호
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• pp.354-362
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• 2019

In order to apply thermoplastic composites using PETG resin to various industrial fields such as bicycle frames and industrial parts, it is necessary to verify the impact resistance, durability and mechanical properties of the manufactured composite materials. To improve the mechanical properties, durability and impact resistance of PETG resin, an amorphous resin, in this study, compound and injection molding process were carried out using various additives such as TiO2, carbon black, polyolefin elastomer, and PETG amorphous resin. The thermal and mechanical properties of the thermoplastic composites, and the Charpy impact strength. The analysis was performed to evaluate the characteristics according to the types of additives. DSC and DMA analyzes were performed for thermal properties, and tensile strength, flexural strength, and tensile strength change rate were measured using a universal testing machine to evaluate mechanical properties. Charpy impact strength test was conducted to analyze the impact characteristics, and the fracture section was analyzed after the impact strength test. In the case of POE material-added thermoplastic composites, thermal and mechanical properties tend to decrease, but workability and impact resistance tend to be superior to those of PETG materials.

• Journal of Biosystems Engineering
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• 제28권3호
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• pp.239-244
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• 2003

The potential use of ultrasonic technique for firmness measurement of apples was evaluated. Mechanical properties(bioyield deformation, bioyield strength, rupture deformation, ultimate strength, and elastic modulus) and ultrasonic parameters (ultrasonic velocity, attenuation coefficient and the first peak frequency) of the apple flesh during the storage time were measured and analyzed. Ultrasonic parameters were determined from the measurement of ultrasonic wave transmission through the apple flesh specimen. Mechanical properties were obtained by universal testing machine. The bioyield strength, rupture strength, elastic modulus, ultrasonic velocity, and the first peak frequency of the apple flesh decreased with the storage time. The bioyield deformation, rupture deformation, and ultrasonic attenuation coefficient increased with the storage time. The correlation analysis between ultrasonic parameters and mechanical properties and the storage time was performed. The high correlations were found between the storage time and the ultrasonic parameters, and these relationships seem to be useful for determining the firmness of the apple flesh.

• 한국안전학회지
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• 제27권1호
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• pp.26-31
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• 2012

Wood-plastic composites represents a growing class of materials used by the residential construction industry and furniture industry. In this study, the effect of flame retardants on the flammability and mechanical properties of wood flour-high density polyethylene(HDPE) composites were studied. we were manufactured wood flour-HDPE composites by modular intermeshing co-rotating twin screw extruder with L/D ratio of 42. The flame retardant properties were used limiting oxygen index(LOI) and mechanical properties were measured by universal testing machine(UTM). The Morphological analysis of composites were analyzed by Scanning electron microscope(SEM). It was found that Ammonium polyphosphate can effectively reduce the flammability of the wood flour-HDPE composites. Marginal reduction in the mechanical properties of the composites was found with addition of flame retardants. SEM images showed that the coupling agent improved wood flour-HDPE interfacial bonding.

• 한국음향학회지
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• 제10권3호
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• pp.13-18
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• 1991

본 연구에서는 취약한 고체의 표면에 존재하는 crack에 탄성표면파를 입사 시켰을 때 발생하는 반사계수를 측정하여 파괴응력을 해석하는 방법을 연구 분석하였다. Crack이 존재하는 취약한 고체에서의 파괴응력은 임계응력확대계수와 정규화된 최대응력확대계수의 함수로써 나타나며, 이 때 정규화된 최대응력확대계수는 탄성표면파의 반사계수를 측정하여 구할 수 있었다. 실험을 위하여 Pyrex glass원판 중앙에 깊이가 0.5mm~0.9mm인 crack을 제작하였고, SAW wedge transducer를 피치캐치(pitch-catch) 모드로 구성하여 반사계수를 측정하고 파괴응력값을 산출하였으며 UTM(Universal Testing Machine)으로 측정한 값과 비교 분석하였다.

• 한국응용과학기술학회지
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• 제28권4호
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• pp.402-409
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• 2011

Compatibility and properties of PP/N66 blends with or without PP-g-MAH as a compatibilizer were investigated by DSC, SEM and universal testing machine. Morphological studies revealed that PP and N66 were incompatible and addition of PP-g-MAH was very effective to enhance the compatibility between PP and N66. The compatibilization effect between N66 and PP-g-MAH was based on the reaction between the amine end group of N66 and anhydride group in PP-g-MAH. The crystallization and melting behavior of PP/N66 blends were investigated and the results of analyses for enthalpy changed were discussed. The Izod impact strength could be improved by optimizing the compatibilizer concentration. Tensile strength, elongation at break, notched Izod impact strength were increased with using compatibilizer, however, both the compatibilized and the noncompatibilizer blends did not show any big difference in the flexural modulus.

• Elastomers and Composites
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• 제35권4호
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• pp.296-302
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• 2000

신발 중창용 EVA 발포체의 수용성 폴리우레탄계 접착제에 대한 접착력을 증가시키기 위하여 발포체 표면을 저온 플라즈마 처리하였다. 플라즈마 처리기체 종류, 플라즈마 처리시간, 전극과 시료와의 거리등의 조건에 따른 발포체의 표면형태, 접촉각 및 수성폴리우레탄에 대한 접착력 등을 주사전자현미경, 접촉각 측정기, 인장강도시험기 등을 사용하여 측정하였다. 플라즈마 처리시간이 증가함에 따라 플라즈마 에칭에 의한 표면 형태의 변화가 더욱 뚜렷하게 나타났으며, 물로 측정한 발포체의 표면 접촉각은 현저히 감소하였다. 플라즈마 처리시간이 증가함에 따라 접착력은 현저히 증가하였다.

• Elastomers and Composites
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• 제46권2호
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• pp.158-163
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• 2011

해수 하에서 경시 변화에 따른 경질 폴리우레탄 폼(PUF)의 물성 변화를 알아보기 위해 방향족 폴리에스테르 폴리올, 지방족 폴리에스테르 폴리올과 지방족 폴리에테르 폴리올 함량에 따라 경질 폴리우레탄 폼을 합성하였다. 해수 하에서 PUF의 물성변화를 고찰하기 위해 만능시험기, 시차 주사 열량계, 경도 측정기, 적외선 분광계를 이용하였다. 방향족 폴리에스테르 폴리올의 함량이 증가함에 따라 해수 하에서 경시 변화에 따라 PUF의 압축강도와 경도의 감소폭은 증가하였다. 해수 하에서 PUF의 유리전이온도는 증가하였는데 적외선 스펙트럼 분석 결과 우레탄과 우레아의 피크는 감소하고, 알로파네이트와 바이우렛의 피크는 증가한 것을 알 수 있었다. 해수 하에서 PUF는 가교도가 증가하여 폼이 brittle하게 형성됨에 따라 유리전이온도가 증가하였지만 가수 분해로 인하여 기계적 물성이 저하된 것으로 사료 된다.