• 한국재료학회:학술대회논문집
• /
• 한국재료학회 1992년도 춘계학술발표회
• /
• pp.146-146
• /
• 1992

• 한국고분자학회지:고분자과학과기술
• /
• 제10권1호
• /
• pp.107-112
• /
• 1999

• 한국식품과학회지
• /
• 제20권3호
• /
• pp.331-337
• /
• 1988

국내에서 생산되는 다수확계 및 일반계 쌀 각 5품종을 Differential Scanning Calorimetry(DSC)로 열분석 하여 호화, amylose-lipid complex의 melting 및 노화 등의 상전이 현상들을 연구하였다. 다수확계와 일반계품종간에는 호화개시 온도에 있어서는 특정한 차이가 없었으나 호화의 온도범위는 다수확계가 약간 넓은 경향이었는데 다수확계가 더 큰 값을 보였다. 고단백 쌀가루의 DSC thermogram은 온도범위가 좁아지고 크기가 작아진 호화 peak를 보여주었다. 노화현상을 DSC방법과 diastase 측정방법을 이용하여 측정한 결과 DSC방법이 보다 우수함을 알았고 다수확계 삼강품종의 노화속도는 일반계 추청품종보다 빠른 것을 알 수 있었다.

• Elastomers and Composites
• /
• 제22권4호
• /
• pp.333-339
• /
• 1987

A modern kinetic evaluation method for nonisothermal reactions measured with Differential Scanning Calorimetry(DSC) is presented. It is based on multiple linear regression analysis using a number of curve points in a selectable range of conversion. The obtained kinetic data are the basis to compute a reaction process under any condition e.g. isothermal or adiabatic. The DSC measurements was performed on a Mettler TA3000 SYSTEM with the built in evaluation software. Mainly the following reactions are discussed: vulcanization of natural rubber compounds containing vulcanizing accelerators. The purpose of this work is to analyse the vulcanization kinetics of typical NR vulcanization systems using DSC. These systems were chosen because they are typically reactive elastomer and are commercially important.

• Composites Research
• /
• 제33권2호
• /
• pp.44-49
• /
• 2020

본 연구에서는 시차주사 열량계(differential scanning calorimetry, DSC)를 이용하여 진공백 성형 공정에 사용되는 탄소 섬유 프리프레그의 경화 거동을 연구하였다. 프리프레그를 이용한 동적주사 시험을 통해 전체 발열량(ΔH_total = 537.1 J/g)을 측정하였고, 130℃~180℃에서 등온주사 시험을 실시하였다. 등온주사 시험의 결과는 온도가 올라감에 따라 발열 반응이 증가되는 것을 확인하였다. 시험 결과를 토대로 수지의 경화 거동을 분석하기 위하여 Kratz 모델을 적용하였다. 서로 다른 경화 사이클로 제작된 평판의 경화도를 경화 예측 모델과 실험값을 비교하였다. 경화 예측 모델은 실험값 대비 3.4% 이하의 오차율을 보여 결과가 잘 부합하는 것을 확인하였다.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2000년도 추계학술발표대회 논문집
• /
• pp.38-41
• /
• 2000

High temperature cure characteristics of polyester resin systems were investigated by isothermal and dynamic differential scanning calorimetries. During isothermal scanning, the experimental procedure was modified to reduce the initial Boss of heat. no kinetic equation from the isothermal experiment was compared with that from the dynamic experiment.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
• /
• pp.172-178
• /
• 2017

열적 특성은 에너지 물질 분야에서 중요한 특성 중 하나로, 에너지 물질 분해 시 분해열을 방출하기 때문에 DSC(시차 주사 열량계, Differential Scanning Calorimetry)를 자주 사용하고 있다. 승온속도를 달리한 DSC 측정의 경우, 용융과 같은 열역학적 변화로 인해 물질의 열적 측정에 방해를 준다. 또한 kg 단위로 예측하기 때문에 mg 단위 때와는 다른 공간상의 열 변화의 변수가 생긴다. 이번 연구에서는 이 문제점을 해결하는 방안으로, 등온 조건으로 한 DSC(Differential Scanning Calorimetry) 기초 데이터로 ATKS thermokinetic 프로그램을 이용하여 열적 노화 특성을 예측한다. 그리고 g 단위로 측정하는 ARC(Accelerating Rate Calorimetry)의 데이터를 이용하여 열적 노화 특성을 예측하고 결과를 비교 할 것이다.

• BMB Reports
• /
• 제35권5호
• /
• pp.472-475
• /
• 2002

Phaseolus vulgaris phytohemagglutinin L is a homotetrameric-leucoagglutinating seed lectin. Its three-dimensional structure shows similarity with other members of the legume lectin family. The tetrameric form of this lectin is pH dependent. Gel filtration results showed that the protein exists in its dimeric state at pH 2.5 and as a tetramer at pH 7.2. Contrary to earlier reports on legume lectins that possess canonical dimers, thermal denaturation studies show that the refolding of phytohemagglutinin L at neutral pH is irreversible. Differential scanning calorimetry (DSC) was used to study the denaturation of this lectin as a function of pH that ranged from 2.0 to 3.0. The lectin was found to be extremely thermostable with a transition temperature around $82^{\circ}C$ and above $100^{\circ}C$ at pH 2.5 and 7.2, respectively. The ratio of calorimetric to vant Hoff enthalpy could not be calculated because of its irreversible-folding behavior. However, from the DSC data, it was discovered that the protein remains in its compact-folded state, even at pH 2.3, with the onset of denaturation occurring at $60^{\circ}C$.

• BMB Reports
• /
• 제39권2호
• /
• pp.167-170
• /
• 2006

Bovine adenosine deaminase undergoes a nondenaturational conformational change at $29^{\circ}C$ upon heating which is characterized by a large increase in heat capacity. We have determined the transition state thermodynamics of the conformational change using a novel application of differential scanning calorimetry (DSC) which employs very slow scan rates. DSC scans at the conventional, and arbitrary, scan rate of $1^{\circ}C/min$ show no evidence of the transition. Scan rates from 0.030 to $0.20^{\circ}C/min$ reveal the transition indicating it is under kinetic control. The transition temperature $T_t$ and the transition temperature interval ${\Delta}T$ increase with scan rate. A first order rate constant $k_1$ is calculated at each $T_t$ from $k_1\;=\;r_{scan}/{\Delta}T$, where $r_{scan}$ is the scan rate, and an Arrhenius plot is constructed. Standard transition state analysis reveals an activation free energy ${\Delta}G^{\neq}$ of 88.1 kJ/mole and suggests that the conformational change has an unfolding quality that appears to be on the direct path to the physiological-temperature conformer.

• 한국응용과학기술학회지
• /
• 제13권3호
• /
• pp.127-136
• /
• 1996

Thermograms of methylene blue(MB) in $L-{\alpha}-lecithin$ vesicle and incorporated purple membrane vesicle(InPM) systems have been studied by photochemical reaction differential scanning calorimetry at $25{\sim}55^{\circ}C$. Phase transition temperatures of lecithin vesicle, purple membrane(PM), and InPM were found to be independent of illumination of light(436nm) at $39{\sim}40^{\circ}C$, but endothermic phase transition was found in InPM vesicle. In MB-InPM system, endothermic phase transition was found on unillumination of light at $40{\sim}42^{\circ}C$, but exothermic phase transition was found on steady illumination of light at $48{\sim}52^{\circ}C$. It was estimated that the light energy absorbed from MB on vesicular surface was transferred to PM, and the transferred energy was redistributed to hydrophobic site of membrane. Therefore, the exothermic phase transition was measured at high temperature because of the increased hydrophobicity of acyl chain.