• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.12
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• pp.1223-1229
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• 2001

Though conventional calorimetry methods such as differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are used generally in measuring heat of fusion, T-history method has the advantages of a simple experimental apparatus and no requirements of sampling process, which is particularly useful for measuring thermal properties of inhomogeneous phase change materials (PCMs) in sealed tubes. However, random criteria (a degree of supercooling) used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion. In the present study, it was shown that a 40% discrepancy exists between the original T-history and the present methods when analyzing the same experimental data. As a result, a reasonable modification to the original T-history method is proposed.

• Korean Journal of Materials Research
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• v.5 no.4
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• pp.405-411
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• 1995

급냉응고된 Al-3.51wt%Li-0.34wt%Zr 합금의 시효거동을 시차주사열량계(DSC)에 의한 열분석 방법으로 조사하였다. DSC에 의한 비열측정 결과 $\delta$’의 석출에 의한 발열반응과 $\delta$, $\beta$ 및 복합석출상의 석출에 의한 발열반응을 확인하였으며 $\delta$’ 및 $\delta$의 재고용에 의한 2개의 흡열반응을 확인하였다. 7$0^{\circ}C$ 저온시효시 $\delta$’의 석출에 의한 발열반응 이전에 흡열반응이 나타났으며 이것은 $\delta$’ 석출 이전에 $\delta$’ 전구생성물이 형성되었음을 의미한다. DSC 곡선상에 나타난 발열과 흡열곡선을 해석하여 얻은 $\delta$’상 석출과 재고용의 활성화에너지값은 각각 83KJ/mol과 98KJ/mol로서 Al-Li 2원계 및 Al-Li-Mg에 비해 높은 값을 나타내엇으며, 시효에 의한 강화가 일어나 DSC에 의한 비열변화 조사결과 나타난 $\delta$’상 석출 완료 시효조건점 (21$0^{\circ}C$, 1시간)에서 최고경도값(Hv 160)을 나타내었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.230-234
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• 1993

In order to obtain the fundamental factors influencing on gelation of Alaska pollack meat paste during processing, the states of water in gel from meat paste were studied using differential scanning calorimetry(DSC) and thermogravimetry(TG). In the differential scanning calorimetry, the calorimetric curves of gels were characterized by single peak through the evaporation of water. Each curve was divided into two divisions below and above $105^{\circ}C(Q_1\;and\;Q_2)$, and a quotient, $R_{105}[={Q_2/(Q_1+Q_2)}+100]$ was adopted to represent the amount of immobilized water in the total water of gels. There was a good correlationships between gel strength values and those quotients($R_{105}$), the correlation coefficient was 0.93. Three types of water(A, B, C) differentiated by evaporating velocity were regarded as free water and it was abundant among the three types of water. The type C water was regarded as the water in so-called mono-molecular layer region. The ratio of the content C versus total water content showed good correlationships with the gel strength and its correlation coefficient was 0.99.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.288-294
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• 1994

Dietary fiber contents in brans of the two representative Korean rice varieties, Chucheong and Sucheon were measured by the AOAC method, and the composition of total dietary fiber (TDF) was analyzed with the acid detergent fiber (ADF) procedure. Rice bran contained more than 25% of TDF, most of which was insoluble dietary fiber. Hemicellulose was shown to be the major constituent and rice bran dietary fiber contained distinctive amounts of cellulose and uronic acid. Consecutive acidalkaline treatment of rice bran considerably increased soluble dietary fiber (SDF) content and water-holding capacity (WHC). WHC of wheat flour-rice bran dietary fiber mixture increased with the proportion of rice bran dietary fiber. Analysis of the differential scanning calorimetry thermograms revealed that rice bran dietary fiber effectively retarded retrogradation of wheat starch.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.51-54
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• 2004

In this paper, the thermal and mechanical properties of elastic epoxy for the application of high voltage products were investigated. Glass transition temperature (Tg) of elastic epoxies cannot be found from room temperature to 20$0^{\circ}C$ by DSC (Differential Scanning Calorimetry). Weight reduction occurred at 285$^{\circ}C$ and 451$^{\circ}C$ according to a thermogravimeter. The first temperature was affected by addictives and the second by epoxies characteristic. Maximum tensile strain showed 28.3kgf/$\textrm{cm}^2$/$\textrm{cm}^2$ at 20% of mechanical stress in addictives 35 (phr). The SEM (Scanning electron microscope) micrograph of the fracture surface observed void and tearing of elastic epoxy at addictives 35 (phr). On the other side, the SEM micrograph of the rigid epoxy showed a broken trace.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1667-1669
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• 2004

In this paper, the elastic epoxy added elastomer having viscoelasticity to existing epoxy was measured thermal, structural properties by DSC (Differential Scanning Calorimetry) and FESEM (Field Emission Scanning Electron Microscope). Specimens were made of dumbbell forms by the ratio of 5, 10, 15, and 20[phr] by regulation with elastomer contents. The measurement temperature dimensions of DSC were -20[$^{\circ}C$] to 150[$^{\circ}C$] and rising temperature was 4[$^{\circ}C$/min]. Also we observed structure through FESEM at the magnification of 1000 times with the voltage of 15[kV] after breaking by quenching specimens. As experimental results, we could know that thermal and structural properties were improved quantity according to decrease of elastomer contents. Namely, it increased glass transition temperature, high temperature, and matrix structure. In general, thermal, structural properties of 15[phr] was excellent among the specimens.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.507-514
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• 1993

The solid state reaction of Mo/Si multilayer thin films produced by RF magnetron sputtering technique was examine dusing differential scanning calorimetry (DSC) and x-ray diffraction, and explained in view of two concepts, effective drivig force and effective heat of formation. In constant scanning rate DSC, there were two exothermic peks which corresponded to the formation of h-MoSi2 and t-MoSi2 , respectively. The activation energyfor theformation of h-MoSi2 was 1.5eV , and that of t-MoSi2 was 7.8eV. Nucleation wa stherate controlling mechanism for each of the silicide formation. Amorphous phase was not formed , which was consistent withtheprediction by the concept of effective driving force. h-MoSi2 the first crystalline phase, was considered to have lower interfacial free energy than t-MoSi2 and by increasing temperature it was transformed into more stable t-MoSi2.

• Journal of Powder Materials
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• v.8 no.1
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• pp.42-49
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• 2001

Ti-50Ni(at%) and Ti-40Ni-10Cu(at%) alloy powders have been fabricated by ball milling method, and their microstructure and phase transformation behavior were investigated by means of scanning electron microscopy/energy dispersive spectrometry, differential scanning calorimetry (DSC), X-ray diffractions and transmission electron microscopy. In order to investigate the effect of ball milling conditions on transformation behavior, ball milling speed and time were varied. Ti-50Ni alloy powders fabricated with the milling speed more than 250 rpm were amorphous, while those done with the milling speed of 100rpm were crystalline. In contrast to Ti-50Ni alloy powders, Ti-40Ni-10Cu alloy powders were crystalline, irrespective of ball milling conditions. DSC peaks corresponding to martensitic transformation were almost discernable in alloy powders fabricated with the milling speed more than 250 rpm, while those were seen clearly in alloy powders fabricated with the milling speed of 100 rpm. This was attributed to the fact that a strain energy introduced during ball milling suppressed martensitic transformation.

• Polymer(Korea)
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• v.24 no.3
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• pp.358-365
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• 2000

Miscibility itnd thermal behavior of blends of synthetic biodegradable aliphatic polyester (Bionolle) with poly(epichlorohydrin) (PECH) were investigated by a differential scanning calorimetry (DSC), a dynamic mechanical thermal analyzer (DMTA) and a rotational rheometer. Observed both single glass transition temperatures from the DSC in agreement with the Fox equation and single T$_{g}$ changes as a function of composition from the DMTA indicate that these blend mixtures are miscible. In addition, the miscibility of this blend system was also observed from the single curve of the Cole-Cole Plot of log G′($\omega$) vs. log C"($\omega$) from the dynamic test using a rotational rheometer. This was further verified from the cryogenically fractured surface of BDP/PECH blends by scanning electron microscopy.

• Advances in materials Research
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• v.2 no.2
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• pp.111-118
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• 2013

The changes of plastic plateau in the stress-strain curves of annealed polypropylene (PP) films during stretching under room temperature were followed and the corresponding melting properties and microstructure were characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). It was found that during stretching the plastic plateau disappeared progressively with the increase of drawing ratio. At the same time, the endotherm plateau in DSC curves also disappeared progressively. The presence of the plastic plateau was attributed to the stretching of unstable crystalline part which was formed by tie chains around initial row-nucleated lamellae structure during annealing. During stretching, the unstable part was stretched and converted to bridges connecting separated lamellae. There was direct relationship between the disappearance of plastic plateau and pore formation.