• Title, Summary, Keyword: 시차 주사 열량 분석

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Sequence Distribution and Thermal Property of Poly(butylene glutarate-co-adipate-co-succinate-co-terephthalate) Copolyesters (Poly(butylene glutarate-co-adipate-co-succinate-co-terephthalate) 공중합체의 서열분포 및 열적성질)

  • Park, Sang Soon;Cho, Yoon;Kang, Hye Jung
    • Journal of the Korean Chemical Society
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    • v.43 no.6
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    • pp.682-690
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    • 1999
  • The quaternary random copolyesters of poly (butylene glutarate-co-adipate-co-succinate-co-terephthalate)(PBGAST) were synthesized and charaterized by $^1H-NMR$ spectrometry, DSC method, and X-ray diffractometry. Thus the melting point trends and crystallization behaviors of PBGAST copolyesters were obviously depended on terephthalate content in copolymers as well as reaction condition.

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A study on the assessment of wildland fire hazard through statistic examination and calorie analysis according to the geographical distribution of vegetation (통계적 고찰과 수목분포에 따른 열량분석을 통한 산림화재 위험성 평가에 관한 연구)

  • 김광일;김동현
    • Fire Science and Engineering
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    • v.14 no.3
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    • pp.27-32
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    • 2000
  • The assessment of wildland fire hazard is the first priority to be considered in the prevention, extinction and control of wildland fire. For the standard to measure wildland fire hazard, the wildland fire Warning System is currently being used in Korea which computes the wildland fire occurrence hazard index through a stick weight to moisture conversion formula. It shows the risk of fuel substance being exposed to fire by meteorological factors. For a comprehensive assessment of wildland fire hazards by area, the major factors'hazards need to be measured and the assessment of wildland fire needs to be conducted through historical statistic examination. Therefore, the wildland (ire outbreak frequency and its seriousness of damage are analyzed through historical statistic examination to conduct the assessment of a wildland fire hazard, and then the calorific value of a forest is analyzed through differential scanning calorimeter measurement which assesses the comparative calorific hazard according to the geographical distribution of vegetation.

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Crystallinity and Mechanical Properties of Glass Fiber Reinforced Thermoplastic Composites by Rapid Press Consolidation Technique (Consolidation 방법에 의해 제작된 유리섬유강화 복합재료의 결정성과 기계적성질에 관한 연구)

  • Shin, Ick-Jae;Kim, Dong-Young;Lee, Dong-Joo
    • Proceedings of the KSME Conference
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    • pp.91-96
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    • 2000
  • Glass fiber reinforced thermoplastic composites were manufactured by Rapid Press Consolidation Technique(RPCT) as functions of temperature, pressure and time in pre-heating, consolidation and solidification sections during the manufacturing processing. It was found that the material property is greatly affected by pre-heating temperature under vacuum, mold temperature and molding pressure. Among them, the temperature In the mold was the most critical factor in determining the mechanical properties and the molded conditions of specimen. The crystallinity of PET matrix was also investigated by differential scanning calorimetry(DSC) measurements for various processing conditions. The level of crystallinity($X_c$) depended strongly on the mold temperature, cooling rate and the type of composite. The difference in $X_c$ is believed to be one of important factors in characterizing the mechanical properties.

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Ag Nano particle dipersed glass fabrication & crystallographical properties (Ag 나노입자 분산유리 제조 및 결정특성평가)

  • 이용수;강원호
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • pp.97-99
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    • 2002
  • 유리내부에 수십나노크기의 Ag 금속입자를 생성시키기 위한 연구를 진행하였다. 본 연구에서는 규산염계 유리에 Ag와 Ce을 첨가하여 환원분위기에서 유리를 제조함으로서 Ce$^{3+}$ 를 유리내에 생성시킬 수 있었으며, 또한 레이저조사(irradiation)를 통하여 Ag+이온의 금속입자 환원을 도울 수 있었다. 또한 레이저 조사시간에 따른 금속입자의 변화를 관찰하고자 하였으며, 이와 같은 과정으로 생성된 금속입자함유 유리를 열처리함으로서 나타나는 열적특성을 평가하여 금속입자가 결정화과정에 미치는 영향을 평가하고자 하였다. 유리내에 존재하는 나노금속입자를 투과전자현미경 (TEM)을 통하여 확인하였으며, 시차주사열량분석법(DSC)을 통해 유리의 결정화거동을 평가하였다. 또한 Photo Luminescence 측정을 통한 유리내부의 Ce이온의 전자상태를 관찰하였다.

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Compatibility Study Using Differential Scanning Calorimetry (시차주사열량분석을 이용한 배합성 연구)

  • Sohn, Young-Taek;Lee, Aea-Kyoung
    • Journal of Pharmaceutical Investigation
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    • v.29 no.2
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    • pp.117-126
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    • 1999
  • Differential scanning calorimetry(DSC) was used as a screening technique for assessing the compatibility of some drugs with excipients. On the basis of DSC results, interaction of ibuprofen with PVP K40 was found and eutectic formations with PEG 6000 or magnesium stearate were demonstrated. Fenoprofen Ca was found to interact with PEG 6000. Naproxen showed interactions with PEG 6000, PVP K40, PVPP and Mg stearate. Interactions of tiaprofenic acid with PVP K40 or PVPP were found and eutectic formations with PEG 6000 or Mg stearate were observed. Bisoprolol hemifumarate, metoprolol tartrate and penbutolol sulfate were found to interact with lactose.

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$Cu(In,Ga)Se_2$ 박막 태양전지 제작을 위한 폴리이미드 기판의 열분석 및 후면전극 특성 분석

  • Park, Su-Jeong;Jo, Dae-Hyeong;Jeong, Yong-Deok;Kim, Je-Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.593-593
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    • 2012
  • CIGS 박막 태양전지는 일반적으로 soda-lime glass(SLG)를 기판으로 사용하여 SLG/Mo/CIGS/CdS/ZnO/ITO/Grid의 구조로 제작된다. 하지만 SLG를 기판으로 사용할 경우, 유리의 특성상 무게가 무겁고, 유연성이 없기 때문에 건축물 적용에 적합하지 않다. 이러한 문제점을 극복하기 위해 가볍고 유연한 금속 및 폴리이미드 기판을 이용한 CIGS 태양전지가 널리 연구되고 있다. 그러나, 폴리이미드 기판의 경우, 특성이 우수한 CIGS 박막을 얻기 위한 고온 공정을 사용할 수 없기 때문에 이에 대한 고려가 필요하다. 본 논문에서는 CIGS 박막 태양전지 제작을 위한 폴리이미드 기판의 특성과 그 위에 형성한 후면 전극의 특성을 논의하고자 한다. 4종류의 폴리이미드 기판에 대한 열 특성을 시차주사열량계(differential scanning calorimeter)와 열중량분석기(thermogravimetric analysis), 열기계분석기(thermo mechanical anaylsis)를 이용해 분석하였다. 또한 Mo 후면 전극을 DC-sputter를 이용해 형성한 후, XRD와 AFM, 4-point probe를 이용하여 결정성 및 표면 거칠기, 면저항을 분석하였다. 결정성과 거칠기는 SLG에 증착했을 때와 동일한 결과를 보였으며, 면저항은 폴리이미드 필름에 증착 할 경우 더 크게 측정되었다. 본 연구는 중소기업청 산연기술개발사업(SL122689) 및 과학기술연합대학원대학교(UST)의 지원을 받아 수행된 "공동연구 지원사업"의 연구결과입니다.

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The Properties Analysis of 600V Grade Polyvinyl Chloride Insulated Wire with Variation of Thermal Stress (열적 스트레스 변화에 따른 600V 비닐절연전선의 특성 분석)

  • 최충석
    • Fire Science and Engineering
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    • v.15 no.1
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    • pp.108-115
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    • 2001
  • In this paper, we analyzed the properties change of electric wire when the thermal stress was applied to 600V grade polyvinyl chloride insulated wire (IV). In the structure analysis, normal wire has the properties of direction on the surface, but in case of deteriorated wire at above $400^{\circ}c$, it formed the carbide, the crack and the crystal. The surface composition rate of normal wire was Cu : 100%, but the section composition of the deteriorated wire at $800^{\circ}c$ showed Cu : 78.89%, O : 21.11%. In result of analyzing the differential scanning calory of copper wire, the new reaction peak was observed on the deteriorated wire at above $700^{\circ}c$. In case of the deteriorated wire as $150^{\circ}c$ at the differential thermal analysis, an endothermic reaction appeared at $264^{\circ}c$ lower than the reactive point of normal wire. The occupation rate of oxygen according to the deterioration of copper wire is about 20% at $500^{\circ}c$.

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Study on the Long-term Thermal Stability by DSC & ARC and its ISCO behaviors with different AP Quality (DSC, ARC, ISCO를 활용한 다양한 순도를 가진 AP의 장기 열적안정성 연구)

  • Kim, Seunghee;Kwon, Kuktae;Lee, So Jung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.2
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    • pp.59-65
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    • 2018
  • We conducted an isothermal slow cook-off(ISCO) test for an aluminized explosive containing AP. The sample bulged before the run-away reaction, and therefore we were unable to obtain the ISCO data. However, these phenomena did not occur for a certain AP grade, which means that the quality of the AP exerted a significant effect on the thermal stability of the explosive formulation. In this study, we investigated the thermal stability difference between a good and bad AP grade. First, we characterized the thermal properties of all APs by Differential Scanning Calorimeter(DSC) and correlated them to the ISCO phenomena. In addition to the DSC study and ISCO test, we also investigated and calculated the SADT and self-heating rate by the ARC of the different AP qualities to interpret the thermal stability of the explosive formulation. Moreover, we investigated the impurity of the AP and a preparation method to remove the included impurity and crystallization. Finally, we implemented qualification methods to identify the quality of AP by DSC using a high-pressure crucible.

Fabrication and Thermophysical Properties of Nickel-coated Aluminum Powder by Electroless Plating (비전해 방법을 이용한 니켈 코팅 알루미늄 분말 제조 및 열물성 평가)

  • Lee, Sanghyup;Lim, Jihwan;Noh, Kwanyoung;Yoon, Woongsup
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.4
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    • pp.9-17
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    • 2014
  • In this study, in order to improve the ignitability of high energy aluminum powder, natural oxide films (alumina) were chemically removed, and instead nickel coat was applied. We used an electroless plating for nickel coating and confirmed quantitatively and qualitatively a time-dependent degree of nickel coating through analysis of surface by SEM/EDS. We also conducted element analysis by XRD and thermal properties by TGA/DSC in air oxidizer environment. There results explained the ignition enhancement mechanism of the nickel-coated aluminum powder in air. The difference between coated and un-coated aluminum powder, the effectiveness of coated powder has better ignitability.

Cure Kinetics and Dynamic Mechanical Properties of an Epoxy/Polyoxypropylene Diamine System (에폭시/폴리옥시프로필렌 디아민계의 경화 반응속도 및 동역학 특성 분석)

  • Huang, Guang-Chun;Lee, Jong-Keun
    • Polymer Korea
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    • v.35 no.3
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    • pp.196-202
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    • 2011
  • The cure kinetics of a bisphenol A epoxy resin and polyoxypropylene diamine curing agent system are investigated in both dynamic and isothermal conditions by differential scanning calorimetry (DSC). In dynamic experiments, the shift of exothermic peaks obtained at different heating rates is used to obtain activation energy of overall cure reaction based on the methods of Ozawa and Kissinger. Isothermal DSC data at different temperatures are fitted to an autocatalytic Kamal kinetic model. The kinetic model is in a good agreement with the experimental data in the initial stage of cure. A diffusion effect is incorporated to describe the later stage of cure, predicting the cure kinetics over the whole range of curing process. Also, dynamic mechanical analysis is performed to evaluate the storage modulus and average molecular weight between crosslinkages.