• Fibers and Polymers
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• 제2권2호
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• pp.75-80
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• 2001

The thermal degradation of poly(ethylene terephthalate-co-isophthalate)s (PETIs) is investigated by using isothermal thermogravimetric analysis at the temperature range of 280-31$0^{\circ}C$. The degradation rate of PETIs is increased as the mole ratio of ethylene isophthaloyl (EI) units in PETIs increases. The activation energies for the thermal degradation of poly(ethylene terephthalate), PETI(5/5), and poly(ethylene isophthalate) are 33.4, 16.6, and 8.9 kcal/mole, respectively. The degradation rate of PETIs is influenced by their volatile cyclic oligomer components formed during the polymerization and the thermal degradation. It is simulated by the rotational isomeric state model that the content of cyclic dimer in PETIs, which is the most volatile cyclic oligomer component, increases with the EI units in PETIs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.154-157
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• 1996

The thin films are fabricated by VDPM and its heat resistant characteristics are investigated using Thermogravimetry. About polyimide, there is a wide difference between 5% weight loss temperature of TG curve and 20,000hr. of life time by methode of ASTM D2307. Therefore, TGI can be obtained by thermogravimetric analysis of NEMA std. pub. NOREI-1974. The TGI was got 670, 674 and 585 at 20$^{\circ}C$, 40$^{\circ}C$ and 70$^{\circ}C$, respectively.

• 한국안전학회지
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• 제21권1호
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• pp.79-85
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• 2006

Olefinic compatibilized blend(R-PP/R-PE)/layered silicate composites have been prepared by melt intercalation technique directed from $Na^{+}$ montmorillonite(MMT) or organophilic montmorillonites while using magnesium hydroxide as flame retardant. Morphology and flammability properties were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), thermogravimetry analysis(TGA), limiting oxygen index(LOI), UL94 test. It is found that the compatibilized blend/layered silicate(Cloisite 20A) nanocomposites have a mixed immiscible-intercalated structure and there is better intercalation when a compatibilizer is combined with the polymer and layered silicate to be melt blended. A very large increase in the LOI value was observed with hybrid filler addition and further enhancement in thermal stability and compatibility of blend was obtained for the compatibilized blend containing small amount of layered silicate.

• 한국건축시공학회지
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• 제11권5호
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• pp.515-522
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• 2011

As Construction and Demolition (C&D) debris increases every year, systems have been adopted to compel the use of recycled aggregate made from C&D debris, and the use of recycled aggregate in the construction field has increased. But environmental problems linked to the alkalinity of recycled aggregate have occurred, and a study on approaches to lower the alkalinity of recycled aggregate is needed. It was certified by this study that a large amount of recycled aggregate could be carbonated in the C&D debris midterm-treatment field. As a result, the density and the water absorption of recycled aggregate after carbonation reaction was improved, and pH of recycled aggregate was lowered from over 11 to 9.4. X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), and Thermogravimetry/Differential Thermal Analysis (TG/DTA) methods also indicated the carbonation of recycled aggregate.

• 신재생에너지
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• 제16권2호
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• pp.47-53
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• 2020

The amount of food waste and its water content depends on both the season and region. In particular, the water content typically varies between 73.8 wt.% and 83.3 wt.%, depending on the proportion of vegetables. Current food waste drying technologies are capable of reducing the water content to less than 10 wt.%, while increasing the heating value. Ongoing studies aim to utilize dried food waste as fuel. Food waste can be used to produce solid refuse fuel (SRF) by mixing it with various solid fuels or other types of waste. The analysis of specimens is very important when considering the direct combustion of food waste or its co-firing with solid fuels. In this study, the weight reduction of specimens after burning them in a small combustor, and compared with the results of thermogravimetric analysis (TGA). The concentration of various chemicals was also measured to define the characteristics of waste generation. Performed proximate analysis, elemental analysis, TGA, combustion experiment, the heating value, and derivative thermogravimetry (DTG).

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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• pp.45-49
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• 2006

탄소/페놀릭 복합재료가 높은 온도에서 열분해 되는 현상을 연구하기 위하여 열중량분석기(TGA)가 이용되었다. 높은 온도와 다양한 하중조건에서 운용되는 고체 추진기관의 열방호 시스템으로 적합한 재료를 분석하고 개발하는데 연구목적이 있다. 실제 연소조건과 유사한 온도 상승속도를 고려하기 위하여 열분해 특성상수 값은 1000 K/min인 경우로 예측된 값을 FEM 해석코드 자료로 활용하였다. 온도 분포는 실험 결과 값과 같은 거동을 보였으며 열분해 깊이는 ${\pm}1mm$ 이내에서 해석 결과와 잘 일치 하였다.

• 한국잠사곤충학회지
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• 제49권2호
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• pp.77-80
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• 2007

실크단백질을 이용한 나노화 소재개발을 위한 기초연구의 일환으로 실크 피브로인과 PVP를 반응시켜 제조한 견단백질/PVP의 열 특성을 살펴보기 위하여 시차열분석 및 열중량분석을 행하였다. 1. PVP의 유리전이온도는 $175^{\circ}C$ 부근에서 관찰되었으며 실크 단백질과 반응에 의하여 영향을 받지 않았으나 견단백질/PVP는 $220^{\circ}C$ 부근에서 미지의 발열피크를 나타내었다. 2. 열중량 분석 결과 PVP의 함량이 증가함에 따라 실크 단백질에 기인한 열분해시작온도가 상대적으로 증가하는 것으로 관찰되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.187-190
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• 1987

This paper is for the charge storage effect and C-V characteristics of MIS type diode which is the basic structural unit of charge-coupled device after growing the $Pb_{1-x}Sn_xTe$ crystal. $Pb_{1-x}Sn_xTe$ singlecrystal dbtained from the horizental furnace using Bridgman method. To judge whether the grown singlecrystal is suitable for specimen or not, it was investigated by X-ray diffraction analysis, thermogravimetry and differential thermal analysis. The C-V characteristics of the specimen caused to anodic oxidation was the best when the insulator film's depth was 250[$\AA$]. Measuring the C-V characteristics aftermanufacturing MIS type diode resulted that the whole capacitance was the largest when the supply voltage was low, 0.3[V] and the capacitance also varied according to the variance frequence when the supply voltage is over 0.5[V]. From the above result, even if the supply voltage is low, the $Pb_{1-x}Sn_xTe$ also have a good charge storage effect.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.908-916
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• 2010

Fullerene-60 nanoparticles were used for studying their effect on the low-density polyethylene (LDPE) biodegradation efficiency of two potential polymer-degrading consortia comprising three bacterial strains each. At a concentration of 0.01% (w/v) in minimal broth lacking dextrose, fullerene did not have any negative influence upon the consortia growth. However, fullerene was found to be detrimental for bacterial growth at higher concentrations (viz., 0.25%, 0.5%, and 1%). Although addition of 0.01% fullerene into the biodegradation assays containing 5mg/ml LDPE subsided growth curves significantly, subsequent analysis of the degraded products revealed an enhanced biodegradation. Fourier transform infrared spectroscopy (FT-IR) revealed breakage and formation of chemical bonds along with the introduction of ${\nu}C$-O frequencies into the hydrocarbon backbone of LDPE. Moreover, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) revealed a higher number of decomposition steps along with a 1,000-fold decrease in the heat of reactions (${\Delta}H$) in fullerene-assisted biodegraded LDPE, suggesting the probable formation of multiple macromolecular byproducts. This is the first report whereby fullerene-60, which is otherwise considered toxic, has helped to accelerate the polymer biodegradation process of bacterial consortia.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.345-353
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• 2013

This paper discusses the experimental results in an effort to understand the tracking and erosion resistance of the micro and nano size $Al_2O_3$ filled silicone rubber (SIR) material which has been studied under the AC voltages, with ammonium chloride as a contaminant, as per IEC 60587 test procedures. The characteristic changes in the tracking resistance of the micro and nano size filled specimens were analyzed through leakage current measurement and the eroded masses were used to evaluate the relative erosion and tracking resistance of the composites. The fundamental, third and fifth harmonic of the leakage current during the tracking study were analyzed using moving average current technique. It was observed that the harmonic components of leakage current show good correlation with the tracking and erosion resistance of the material. The thermogravimetry-derivative thermo gravimetric (TG-DTG) studies were performed to understand the thermal degradation of the composites. The physical and chemical studies were carried out by using scanning electron microscope (SEM), Energy Dispersive X-ray analysis (EDAX) and Fourier Transform Infra-red (FTIR) Spectroscopy. The obtained result indicated that the performance of nano filled SIR was better than the micro filled SIR material when the % wt. of filler increased.