• Journal of the Korean Ceramic Society
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• v.14 no.2
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• pp.95-103
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• 1977

Characteristics of Ham Pyong clay and clay-organic complexes were investigated by means of geological exploration, chemical analysis, X-ray diffraction, differential thermal analysis, electron microscopy, thermal mechanical analysis, cation exchange capacity and viscosity measurement. The results are as follows; 1) This caly is a transported clay which has black and white colors, and the amounts of deposit are estimated about 1, 600, 000M/T. 2) The major mineral phases identified by X-ray diffraction are kaolinite, sericite and halloysite and the minor phases are quartz and feldspar, these mineral phases can be seperated very easily by the elutriation method. 3) It was supposed that the black colored clay involved a certain clay-organic complexs by the mechanism of intercalation as well as surface absorption. 4) The clay-organic complexes in clay seemed to improve dispersity, to increase the fluidity of clay-water slips, to decrease the firing shrinkage and to promote the thermo-chemical reaction at temperature range up to 50$0^{\circ}C$, but not to effect on the resulted firing color.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.532-544
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• 2023

Purpose: To identify and evaluate the risk of chemical fire causative substances by using thermal analysis methods (DSC, TGA) for the hazards and physical property changes that occur when newly used biofuels are mixed with existing fuels It is to use it for identification and evaluation of the cause of fire by securing data related to the method and the hazards of the material according to it. Method: The research method used in this experiment is the differential scanning calorimeter (DSC: Difference in heat flux) through quantitative information on the caloric change from the location, shape, number, and area of peaks. flux) was measured, and the weight change caused by decomposition heat at a specific temperature was continuously measured by performing thermogravimetric analyzer (TGA: Thermo- gravimetric Analyzer). Result: First, in the heat flux graph, the boiling point of the material and the intrinsic characteristic value of the material or the energy required for decomposition can be checked. Second, as the content of biodiesel increased, many peaks were identified. Third, it was confirmed through analysis that substances with low expected boiling points were contained. Conclusion: It was shown that the physical risk of the material can be evaluated by using the risk of biodiesel, which is currently used as a new energy source, through various physical and chemical analysis techniques (DSC + TGA).In addition, it is expected that the comparison of differences between test methods and the accumulation and utilization of know-how on experiments in this study will be helpful in future studies on physical properties of hazardous materials and risk assessment of materials.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.8-12
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• 2000

The properties variation by deterioration of the 600V grade heat-resistant polyvinyl chloride insulated wire(HIV) was analyzed. The weight variation of the thermal deteriorated HIV was about 42% at 80$0^{\circ}C$ and over. From the analysis result of the metallurgical microscope photographs it shows that the sorface of normal wire showed the elongated structures. However the elongated structures did not appear at $900^{\circ} and over and we could observe that particles were grown. The grown oxidized substances in the thermally deteriorated electric wire were observed by SEM. The CuL, CuK, $CuK_b$, OK and CIK spectra of the thermally deteriorated HIV at $300^{\circ}C$ were uniform regardless of the scanning length, but the spectra of CIK could not found at above $700^{\circ}. At the DTA analysis, the endothermic reactions were occurred around $3006{\circ}C\; and\; 400^{\circ}C$ and the exothermic reactions were occurred around $470^{\circ}, respectively.

• Journal of the Korean Ceramic Society
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• v.20 no.3
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• pp.236-242
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• 1983

The purpose of present study is to find the structures physical properties and their inter-relations in the system of (60-x) PbO.xMO.$40B_2O_3$ glasses where MO represents for ZnO and CdO. The experiments such as differential thermal analysis infrared spectral analysis X-ray diffraction analysis density and thermal expansion measurements have been done. From infrared spectral analysis the structural units of glasses and the corresponding crystallized glasses were com-posed of $BO_3$ triangles and $BO_4$ tetrahedra. These basic units found in $PbO-B_2O_3$ binary glass system did not charge even though the divalent metallic oxides were substituted for PbO. The structures of these ternary glasses were more coalescenced than $PbO-B_2O_3$ binary glass system. This fact was supported bydecrease in thermal expansion coeffici-ent and molar volume with substitution of divalent metallic oxide for PbO. Crystalline phases obtained from the heat treatment of the $PbO-ZnO-B_2O_3$ glasses were 4PbO.2ZnO.$5B_2O_3$ PbO.2ZnO.$B_2O_3$ and unknown phases.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.403-408
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• 1996

석탄화력발전소 폐기물인 석탄회와 요오드화 세슘의 반응특성을 DTA(Differential Thermal Analysis), TGA(Thermo-Gravimetric Analysis) 장치를 이용하여 분석하였다. 본연구에 사용된 석탄회는 85%의 실리카와 알루미나를 함유하고 있으며 Si/Al 몰비는 2.1 이었다. DTA와 TGA의 열분석 결과 CsI의 분해, 석탄회와 기체상 세슘의 반응 등으로 이루어져 있다. 석탄회와 CsI의 혼합물은 94$0^{\circ}C$ 이상에서 Pollucite 가 형성되었다. 반응생성물들의 SEM 분석결과 표면이 거칠며 bulky한 crystal 형태로서 구형의 석탄회와는 매우 다른 형상을 보였다. 석탄회는 요오드화세슘의 고정화를 위해서 적합한 알루미노규산염 원료물질들 중의 하나임을 확인하였다.

• Proceedings of the Korean Fiber Society Conference
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• 1996.04a
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• pp.64-68
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• 1996

PP-EVOH(poly(vinyl alchol-co-ethylene)) blends were prepared by the mixing of polypropylene and poly(vinyl alcohol-co-ethylene) containing 38mol% of ethylene units (EVOH38) at melt state above PP melting temperature. The materials were characterized by using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and contact angle measurement to detemine the glass transition, meltin, decomposition temperatures, and wettability respectively. From the results, PP-EVOH(poly(vinyl alcohol-co-ethylene)) blends exgibits partial miscibility.

• YAKHAK HOEJI
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• v.25 no.1
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• pp.37-42
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• 1981

Penicillin derivatives have a stability problem by hydrolysis of their .betha.-lactam ring. At high temperature, crystal water is released from penicillin derivatives, especially ampicillin trihydrate and concerns itself in hydrolysis. Penicillin derivatives having crystal water show different crystal states and different stability according to the variation of different condition on the process of manufacturing. The stability of ampicillin trihydrate in solid states was determined. Physico-pharmaceutical properties of this compound were determined by using IR spectra, X-ray powder diffraction and differential thermal analysis (DTA).

• Economic and Environmental Geology
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• v.18 no.3
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• pp.253-261
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• 1985

Detailed chemical compositions of thirteen montmorillonites and their thermal behaviour by differential thermal and thermogravimetric analysis have been studied. Comparison of structural formulae with experimental results by thermal analysis gave evidence of that both substitutions of Fe for Al in octahedral and Al for Si in tetrahedral positions appear to affect dehydroxylation temperature, which is valid for the present samples. Further detailed study of this topic using well-known samples which have various degree of substitution will be justified.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.4
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• pp.204-209
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• 2017

Thermal and structural stability in the glass transition region of chalcogenide glasses has been investigated in terms of thermodynamics for application to various optoelectronic devices. In this study, the compositions of $Ge_xSb_{20}Se_{80-x}$ (x = 10, 15, 20, 25, and 30) were selected to investigate the glass stability according to germanium ratios. The chalcogenide bulks were fabricated by using a traditional melt-quenching method. Thin films were deposited by a thermal evaporation system, maintaining the deposition ratio of $3{\sim}5{\AA}$ in order to have uniformity. The thermal and structural properties were measured by a differential scanning calorimeter (DSC) and X-ray diffraction (XRD). The DSC analysis provided thermal parameters and theoretical glass region stabilities. The XRD analysis supported the theoretical stabilities because of where the crystallization peak data occurred.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.6
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• pp.293-299
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• 2004

In this paper, thermal and mechanical properties of electric epoxy with water aging were discussed. We made elastic epoxy specimen adding a ratio of 0〔phr〕20〔phr〕, 35〔phr〕 and 53〔phr〕 with modifier to existing epoxy. We studied mechanical property of elastic resin after absorption in water from 0 to 484 hours. As a result, diffusion factor of elastic epoxy showed 20-21${\times}$10$^{-4}$ $\textrm{mm}^2$/s and general epoxy showed 9.5${\times}$10$^{-4}$ $\textrm{mm}^2$/s. Elastic property increased linearly according to addiction and decreased according to water absorption. Tensile strength was reduced according to addition. It was affected by water absorption of micro-void of elastic epoxy. Hardness inclined to decrease after increasing according to absorbed time. In water-absorption state, it was experimented a change of heat flow by temperature of elastic epoxy and change of thermal expansion coefficient. DSC (Differential Scanning Calorimetry) and TMA (Thermomechanical Analysis) equipments were used to measure Tg. A temperature ringe of DSC was from -0($^{\circ}C$) to 200($^{\circ}C$). One of TMA was from -0($^{\circ}C$) to 350($^{\circ}C$). In addition, we investigated structural analysis of water absorbed specimen using SEM (Scanning Electron Microscope).