• 자원리싸이클링
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• 제19권2호
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• pp.19-27
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• 2010

폐목재를 고온고압장치를 사용하여 나무의 결대로 파쇄 후 건축재료로의 활용을 위하여 등급별로 분류하여 열분해 및 파쇄특성을 알아보았다. 그 결과, TG/DTA 그래프에서 $250^{\circ}C$에서 급격한 무게감소가 발생하는데, 건축재료로의 활용을 위해서는 $250^{\circ}C$이하의 온도에서 처리가 되어야 한다. 고압파쇄 실험결과 활엽수보다는 침엽수가 나무의 결대로 잘 찢어짐을 알 수 있었으며, 그 중 편백나무(W-7)가 가장 양호한 결과를 나타내었다. 다양한 조건의 실험결과, 온도는 $200^{\circ}C$, 압력은3MPa이 최적조건임을 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1032-1041
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• 2010

The comparative influence of two nanoparticles [viz., superparamagnetic iron oxide nanoparticles (SPION) and nanobarium titanate (NBT)] upon the in vitro and in situ low-density polyethylene (LDPE) biodegradation efficiency of a potential polymer-degrading microbial consortium was studied. Supplementation of 0.01% concentration (w/v) of the nanoparticles in minimal broth significantly increased the bacterial growth, along with early onset of the exponential phase. Under in vitro conditions, ${\lambda}$-max shifts were quicker with nanoparticles and Fourier transform infrared spectroscopy (FTIR) illustrated significant changes in CH/$CH_2$ vibrations, along with introduction of hydroxyl residues in the polymer backbone. Moreover, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) reported multiple-step decomposition of LDPE degraded in the presence of nanoparticles. These findings were supported by scanning electron micrographs (SEM), which revealed greater dissolution of the film surface in the presence of nanoparticles. Furthermore, progressive degradation of the film was greatly enhanced when it was incubated under soil conditions for 3 months with the nanoparticles. The study highlights the significance of bacteria-nanoparticle interactions, which can dramatically influence key metabolic processes like biodegradation. The authors also propose the exploration of nanoparticles to influence various other microbial processes for commercial viabilities.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.123-128
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• 2001

This study was performed to find out variation of carbonation progress of agricultural hydraulic concrete structures along the used years with using Thermo Gravimetric analysis/Differential Thermal Analysis(TG/DTA) and Indicator(phenolphthalein). In this study some conclusions such as follows were derived. Firstly, The result that the age of structures and the content of $Ca(OH)_{2}\;and\;CaCO_{3}$ in concrete have proportional relationships was found in the method of TG/DTA. This relational functions could be used to estimate remain lifetime of structures, obtaining the limits of the content of $CaCO_{3}$ in concrete which reinforcement corrosion could be occurred with breaking protection cover of alkalinity. Second, if the result of strength, voids, permeability characteristics could be combined with this relational function this may be able to be used as a new more accurate assessment technique for the quality of concrete than current usual methods. Third, environmental affect could be more superintendent for concrete carbonation than the age of agricultural hydration structures. Forth, It is difficult to estimate the used year of agricultural hydraulic concrete structures with the carbonation depth measured by indicator method. Finally, the accuracy of this relational function could be decided to be upgraded with continue analysis for more structures.

• E2M - 전기 전자와 첨단 소재
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• 제10권3호
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• pp.217-225
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• 1997

In this study, the PVDF organic thin film was fabricated by the physical vapor deposition method to be dry-process. The distance of heat source and substrate was 5[cm] and the temperature of substrate was 30[.deg. C], when the pressure had reached 2.0 x 10$^{-5}$ [Torr], the temperature of heat source was reached to 285[.deg. C] to heat at 6-8[.deg. C/min] rate, the shutter was opened and deposition was started. TG-DTA(Thermogravimetric-Differential Thermal Analysis) spectrum of PVDF pellets showed that endothermic peak arose at 170[.deg. C] and exothermic peak at 524[.deg. C], but that of thin PVDF film showed that endothermic peak arose at 145[.deg. C] and exothermic peak at 443[.deg C]. The current density was increased linearly with increasing voltage but increased nonlinearly with higher electric field than 250[kV/cm] and activation energy was about 0.667[eV] at the temperature of 30-90[.deg. C].

• 대한화학회지
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• 제35권6호
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• pp.653-658
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• 1991

Sol-gel법을 통하여 만들어진 비정질 Ta-IPA 괴상과 박막을 $25^{\circ}C$와 $340^{\circ}C$로 열처리한 구조의 차이점과 구조수와의 관계를 TG-DTA, IR과 X-선회절 강도측정으로부터 구한 동경분포곡선 등을 이용하여 알아보았다. 각 시편들을 L-$Ta_2O_5$ 결정의 물성 및 동경분포곡선(calc-RDF)과 비교하였다. 박막은 8면체-$TaO_6$로 괴상보다 작은 cluster로 구성되어 있었다.

• 대한화학회지
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• 제45권2호
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• pp.156-161
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• 2001

여러 가지 산화상태의 폴리아닐린을 화학적으로 합성하여 FT-IR, UV-Vis, GPC, TG-DTA로 측성 분석하였다. ITO 기관위에 다양한 산화상태의 LEB-PAN/NMP 용액으로 스핀코팅하고, AI 전극을 진공증착하여 단일층 발광다이오드를 제작하고 I-V 특성과 EL 스팩트럼에서 완전환원형인 LEB 함량이 증가할수록 ${\pi}$-${\pi}$* 전이의 장파장이동과 분자 엑시톤 전이 세기가 감소하고 PL과 EL 세기가 증가하는 것을 확인하였다. ITO/LEB/AI 구조의 LED에서 작동 전압은 5V 이었다. 백색광은 단지 폴리아닐린의 환원형 구조에서만 발광하는 것을 확인하였다.

• 한국안전학회지
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• 제31권1호
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• pp.61-65
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• 2016

In this study, we considered the ignition possibility for the shredded thermoplastic elastomer at the fire ground loaded the waste TPE. The average moisture content of the TPE sample was almost 0.33 wt.% at $110^{\circ}C$ and the range of ignition point was $461.9{\sim}491.9^{\circ}C$ approximately. In addition, we analyzed the change of weight and calorie the TPE sample according to temperature variations using the TG-DTA analyzer. As a result, the weight loss occurred twice in $250{\sim}420^{\circ}C$ and $420{\sim}473^{\circ}C$, and we found the second weight loss temperature range was the ignition point of TPE. Also, we conducted the spontaneous ignition tests of TPE for the wet and dry samples and we confirmed that the possibility of spontaneous ignition of TPE was very low. The elapsed time and humidity had little influence on the spontaneous ignition of TPE in this experimental conditions. In conclusion, the spontaneous of the shredded waste TPE in this study.

• 한국화재소방학회논문지
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• 제23권1호
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• pp.21-32
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• 2009

본 연구에서는 임내 연료의 산불 위험성을 판단하기 위하여 영동지역에 자생하는 주요 7가지 수종의 낙엽과 생엽을 대상으로 TG/DTA와 발화점 시험기를 이용하여 열적특성과 발화특성을 고찰하였다. 가열속도 변화에 따른 열 중량변화를 분석한 결과, 가열속도가 증가할수록 열적 지연현상이 나타났지만 중량감소율에 따른 잔류량은 차이가 없는 것으로 나타났다. 수종별 온도변화에 따른 열 중량분석 결과, 낙엽과 생엽 모두 침엽수가 활엽수보다 총중량감소율이 큰 것으로 나타났다. 발화특성에 대한 분석결과로는 낙엽과 침엽수의 자연발화온도가 낮고 열에 대한 저항성이 낮기 때문에 생엽과 활엽수보다 발화 위험성이 높은 것으로 나타났다.

• 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.

• Elastomers and Composites
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• 제33권3호
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• pp.201-209
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• 1998

고무배합물의 충진제로 사용되는 알루미나 분말의 제조에 있어서 재래식 및 마이크로파 에너지원에 의하여 황산용액중의 카올린으로 부터 알루미나를 얻는다. 이때 카올린으로부터 알루미나 분말의 최대 추출율은 각각 재래식의 경우는 $80^{\circ}C$, 1M 황산, 180분에서 72.8%이고, 마이크로파 추출 공정의 경우는 $90^{\circ}C$, 1m 황산, 60분에서 $99\%$였다. 또한 추출된 시료는 TG/DTA, XRD, SEM, Atomic Emission Spectroscopy 및 BET법에 의하여 분석하였다..