• 제목/요약/키워드: Differential Scanning Calorimetry (DSC)

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습식 및 건식 쌀가루의 유지 종류 및 첨가 비율에 따른 쌀빵 품질 특성 (Effects of the Type and Percentage of a Lipid on the Quality Characteristics of Rice Bread Depending on the Use of Wet and Dry Rice Flour)

  • 김상숙;정혜영
    • 한국식품영양학회지
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    • 제31권4호
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    • pp.511-519
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    • 2018
  • The baking properties of rice bread with different percentages of butter and oil in wet and dry rice flour were investigated. The moisture, damaged starch, mean diameter, pasting properties by amylogram and RVA (Rapid Visco Analyzer), as well as thermal properties by DSC (Differential Scanning Calorimetry) of wet and dry rice flour were analyzed. The specific gravity and color (L, a, b) of the dough, as well as the appearance, color (L, a, b) and texture of the rice bread with different percentages of butter and oil in wet and dry rice flour were also analyzed. As a result, the wet rice flour were composed of a noted higher content in moisture, compared to the dry rice flour (p<0.001). The wet rice flour had lower values of damaged starch, higher values of mean diameter and a higher peak viscosity than was noted in the dry rice flour (p<0.001). The wet rice flour showed a higher degree of hydration and gelatinization than was seen in the dry rice flour (p<0.001). The prevailing principle to utilize the replacement of wet rice flour with oil had a significant effect on the volume, specific volume and hardness of the rice bread (p<0.001). The hardness of the rice bread also showed a decreasing trend as the amount of the added oil was increased into the mixture. These results suggest that the replacement of wet rice flour with 5.8% oil is effective for the production of rice bread.

에폭시 수지에 따른 언더필의 특성에 관한 연구 (Characteristic of Underfill with Various Epoxy Resin)

  • 노보인;이종범;정승부
    • 마이크로전자및패키징학회지
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    • 제13권3호
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    • pp.39-45
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    • 2006
  • 다양한 에폭시 수지를 함유한 언더필의 열적 특성을 시차주사열량측정법, 열중량측정법, 동적-기계적 분석법, 열적-기계적 분석법과 같은 열 분석법을 이용하여 분석하였다. 또한, 언더필과 FR-4기판 사이의 접합 강도를 측정하였다. Cycolaliphatic 에폭시 수지를 함유한 언더필의 유리 전이 온도가 cycolaliphatic 에폭시 수지를 함유하지 않은 언더필의 유리 전이 온도보다 낮음을 확인할 수 있다. 대기로부터 유입된 산소와 열화된 폴리머 사이의 화학적 반응으로 인하여 언더필의 열적 감소 반응이 두 번 발생하는 것을 확인할 수 있다. Cycolaliphatic 에폭시 수지를 함유한 언더필의 열팽창 계수가 cycolaliphatic 에폭시 수지를 함유하지 않은 언더필의 열팽창 계수보다 높음을 확인할 수 있다. 과도한 경화 온도는 에폭시 수지의 경계면을 약하게 하여 에폭시 수지의 기계적 특성의 변화를 초래하게 되고 언더필과 FR-4 기판 사이의 접합 특성을 저하시키게 된다.

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수산화마그네슘 분산상의 제조와 PET 부직포 섬유의 난연 코팅제 적용 (Preparation of Mg(OH)2 Dispersion and its Application to PET Non-woven Textile as Flame Retardant Coating)

  • 임형미;현미경;정상옥;이동진;이승호
    • 한국세라믹학회지
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    • 제48권6호
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    • pp.537-542
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    • 2011
  • Magnesium hydroxide as a non-halogen flame retardant has increasing attention due to its non-toxicity, high decomposition temperature and smoke suppressant ability during combustion. For the application of magnesium hydroxide retardant to the textile by soaking and coating method, the prerequisite for the coating is a small particle size, stable dispersion, and adhesion to the textile. The dispersion of $Mg(OH)_2$ particles and stability of the coating was checked by monitoring the change of transmittance and backscattering by varying the types of dispersion agents, binder, solvent, and $Mg(OH)_2$ source, and their compositions in the coating. The $Mg(OH)_2$ dispersion coating was applied to PET(poly(ethylene terephthalate)) non-woven textile. The physical properties are characterized by surface morphology, amount of coating, particle dispersion, and adhesion test. The flame retardant $Mg(OH)_2$ coated textile has been compared by limited oxygen index(LOI) and thermal gravimetry and differential scanning calorimetry(TG-DSC). It was found that phosphorous additive may give synergistic effect on $Mg(OH)_2$ flame retardant coating to make the flame retardant PET non-woven textile.

중합체 매개 용융압출에 의한 참당귀 나노복합체의 제조 (Fabrication of Nano-composites from the Radix of Angelica gigas Nakai by Hot Melt Extrusion Mediated Polymer Matrixs)

  • ;조현종;임정대;박철호;강위수
    • 한국약용작물학회지
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    • 제26권5호
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    • pp.417-429
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    • 2018
  • Background: The objective of this study was to make colloidal dispersions of the active compounds of radix of Angelica gigas Nakai that could be charaterized as nano-composites using hot melt extrusion (HME). Food grade hydrophilic polymer matrices were used to disperse these compound in aqueous media. Methods and Results: Extrudate solid formulations (ESFs) mediated by various HPMCs (hydroxypropyl methylcelluloses) and Na-Alg polymers made from ultrafine powder of the radix of Angelica gigas Nakai were developed through a physical crosslink method (HME) using an ionization agent (treatment with acetic acid) and different food grade polymers [HPMCs, such as HP55, CN40H, AN6 and sodium alignate (Na-Alg)]. X-ray powder diffraction (XRD) analysis confirmed the amorphization of crystal compounds in the HP55-mediated extrudate solid formulation (HP55-ESF). Differential scanning calorimetry (DSC) analysis indicated a lower enthalpy (${\Delta}H=10.62J/g$) of glass transition temperature (Tg) in the HP55-ESF than in the other formulations. Infrared fourier transform spectroscopy (FT-IR) revealed that new functional groups were produced in the HP55-ESF. The content of phenolic compounds, flavonoid (including decursin and decursinol angelate) content, and antioxidant activity increased by 5, 10, and 2 times in the HP55-ESF, respectively. The production of water soluble (61.5%) nano-sized (323 nm) particles was achieved in the HP55-ESF. Conclusions: Nano-composites were developed herein utilizing melt-extruded solid dispersion technology, including food grade polymer enhanced nano dispersion (< 500 nm) of active compounds from the radix of Angelica gigas Nakai with enhanced solubility and bioavailability. These nano-composites of the radix of Angelica gigas Nakai can be developed and marketed as products with high therapeutic performance.

채취 시기별 칡 전분의 성질 비교 (Comparison of Physicochemical Properties of Arrowroot Starches Harvested in Different Time)

  • 박종훈;나환식;강길진;김관;김성곤
    • 한국식품과학회지
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    • 제30권1호
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    • pp.97-102
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    • 1998
  • 칡을 3, 6, 9, 12월에 채취하여 분리한 전분의 성질을 비교한 결과 12월 전분은 아밀로오스 함량, 고유점도, 베타-아밀라아제 분해한도가 가장 작았으나, 물결합능력은 가장 컸다. 팽윤력은 채취 시기별로 큰 차이를 보이지 않았다. KSCN에 의한 호화에서 12월 시료는 겔의 부피증가 정도가 가장 작았고 평형 부피에 도달하는 시간도 가장 늦었다. DSC에 의한 호화온도는 12월 시료는 다른 시료보다 $1^{\circ}C$ 높았다. 열수가용성 전분의 조성은 12월 시료가 아밀로오스 함량이 가장 높았고 아밀로펙틴은 가장 낮았다. 이러한 결과 칡 전분은 채취시기에 따라 그 성질이 다름을 알 수 있었다.

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154kV 전력케이블용 XLPE 절연체와 반도전 재료의 비열 및 열전도 (Specific Heat and Thermal Conductivity of XLPE Insulator and Semiconductive Materials for 154kV Power Cable)

  • 이경용;양종식;최용성;박대희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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    • pp.19-24
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    • 2005
  • To improve mean-life and reliability of power cable, we have investigated specific heat (Cp) and thermal conductivity of XLPE insulator and semiconductive materials in 154kV underground power transmission cable. Specimens were respectively made of sheet form with EVA, EEA and EBA added 30wt%, carbon black, and the other was made of sheet form by cutting XLPE insulator in 154kV power cable. Specific heat (Cp) and thermal conductivity were· measured by DSC (Differential Scanning Calorimetry) and Nano Flash Diffusivity. Specific-heat measurement temperature ranges of XLPE insulator were from 20[$^{\circ}C$] to 90[$^{\circ}C$], and the heating rate was 1[$^{\circ}C$/min]. And the measurement temperatures of thermal conductivity were 25[$^{\circ}C$}], 55[$^{\circ}C$] and 90[$^{\circ}C$]. In case of semiconductive materials, the measurement temperature ranges of specific heat were from 20[$^{\circ}C$] to 60[$^{\circ}C$], and the heating rate was 1[$^{\circ}C$/min]. And the measurement temperatures of thermal conductivity were 25[$^{\circ}C$] and 55[$^{\circ}C$]. From these experimental results, both specific heat and thermal conductivity were increased by heating rate because volume of materials was expanded according to rise in temperature.

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Thermal Stability, Mechanical Properties and Magnetic Properties of Fe-based Amorphous Ribbons with the Addition of Mo and Nb

  • Han, Bo-Kyeong;Jo, Hye-In;Lee, Jin Kyu;Kim, Ki Buem;Yim, Haein
    • Journal of Magnetics
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    • 제18권4호
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    • pp.395-399
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    • 2013
  • The metallic glass ribbons of $[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}]_{96}Mo_4$ (x = 0, 0.3, 0.6, 0.9 at.%) and $[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}]_{96}Nb_4$ (x = 0, 0.3, 0.6, 0.9 at.%) were obtained by melt spinning with 25-30 ${\mu}m$ thickness. The thermal stability, mechanical properties and magnetic properties of Fe-Co-B-Si based systems were investigated. The values of thermal stability were measured using differential scanning calorimetry (DSC), including glass transition temperature ($T_g$), crystallization temperature ($T_x$) and supercooled liquid region (${\Delta}T_x=T_x-T_g$). These amorphous ribbons were identified as fully amorphous, using X-ray diffraction (XRD). The mechanical properties of Febased samples were measured by nano-indentation. Magnetic properties of the amorphous ribbons were measured by a vibrating sample magnetometer (VSM). The amorphous ribbons of $[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}]_{96}Mo_4$ (x = 0, 0.3, 0.6, 0.9 at.%) and $[(Fe_xCo_{1-x})_{0.75}B_{0.2}Si_{0.05}]_{96}Nb_4$ (x = 0, 0.3, 0.6, 0.9 at.%) exhibited soft magnetic properties with low coercive force ($H_c$) and high saturation magnetization (Ms).

BCNU 함유 PLGA 웨이퍼의 제조와 생체외 방출거동 (Preparation of BCNU-loaded PLGA Wafers and In Vitro Release Behavior)

  • 성하수;문대식;강길선;이정식;이해방
    • 폴리머
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    • 제26권1호
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    • pp.128-138
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    • 2002
  • 종양부위 또는 종양을 수술로 제거한 부위에 직접 이식하여 항암제를 투여함으로써 종양 또는 종양재발을 억제하는 악성뇌종양치료에 이용하기 위한 국소서방성 항암제제로서 항암제 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, Carmustine)가 함유된 poly(D,L-lactide-co-glycolide) (PLGA, 락타이드와 글리콜라이드 몰비 75 : 25) 미분말을 제조하여 웨이퍼로 성형하였다. BCNU가 함유된 PLGA 미분말은 분사건조법에 의해 제조하였으며 주사전자현미경으로 관찰한 결과 제조된 미분말은 미립구의 형태를 나타내었다. XRD와 DSC를 통하여 PLGA에 포접된 BCNU의 결정성이 현저히 감소하였음을 확인하였다. 생체외 방출시험조건에서 BCNU의 방출경향은 PLGA의 분자량 및 농도, BCNU의 함량 등에 의존하였으며 초기 burst effect 이후 거의 0차 방출의 경향으로 8주 이상 지속적인 방출경향을 나타내었다. 방출시험기간 동안 웨이퍼의 형태변화를 관찰하고 방출시험액의 pH 변화를 측정함으로써 BCNU의 함량이 증가할수록 PLGA의 수화와 분해가 촉진됨을 확인하였다.

Functionalized Emulsion Styrene-Butadiene Rubber Containing Diethylaminoethyl Methacrylate for Silica Filled Compounds

  • Park, Jinwoo;Kim, Kihyun;Lim, Seok-Hwan;Hong, Youngkun;Paik, Hyun-jong;Kim, Wonho
    • Elastomers and Composites
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    • 제50권2호
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    • pp.110-118
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    • 2015
  • In this study, diethylaminoethyl methacrylate-styrene-butadiene terpolymer (DEAEMA-SBR), in which diethylaminoethyl methacrylate (DEAEMA) was introduced to the SBR molecule as a third monomer, was synthesized by cold emulsion polymerization. It is expected that amine group introduced to a rubber molecule would improve dispersion of silica by the formation of hydrogen bond (or ionic coupling) between the amine group and silanol groups of silica surface. The chemical structure of DEAEMA-SBR was analyzed using proton nuclear magnetic resonance spectroscopy (H-NMR), Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Then, various properties of DEAEMA-SBR/silica composite such as crosslink density, bound rubber content, abrasion resistance, and mechanical properties were evaluated. As a result, bound rubber content and crosslink density of DEAEMA-SBR/silica compound were higher than those of the SBR 1721 composite. Abrasion resistance and moduli at 300% elongation of the DEAEMA-SBR/silica composite were better than those of SBR 1721 composite due to the high bound rubber content and crosslink density. These results are attributed to high affinity between DEAEMA-SBR and silica. The proposed study suggests that DEAEMA-SBR can help to improve mechanical properties and abrasion resistance of the tire tread part.

Process Optimization for Preparing High Performance PAN-based Carbon Fibers

  • Yun, Jeong-Hyeon;Kim, Bo-Hye;Yang, Kap-Seung;Bang, Yun-Hyuk;Kim, Sung-Ryong;Woo, Hee-Gweon
    • Bulletin of the Korean Chemical Society
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    • 제30권10호
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    • pp.2253-2258
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    • 2009
  • wet spun polyacrylonitrile (PAN) fiber precursors. The process variables chosen were treatment temperature, applied tension in stabilization process. The temperature profile of the stabilization was set on the basis of exothermic peaks of the differential scanning calorimetry (DSC) result. Both tensile strength and modulus increased with holding at onset temperatures of the exothermic peaks for extended duration, and with a higher heating rate up to the onset temperatures at a given applied tension among the experimental conditions. The increase in load monotonously increased the tensile modulus, on the other hand, the tensile strength was maximum at the load of 15 mg/filament (T15). The load 20 mg/ filament (T20) was considered to be exceeded to form oriented crystalline structure, possibly introducing more defects in the fiber than under load of T15. The sample CP3-T15 O5 H30 showed the best tensile properties among the samples experimented whose tensile properties are compatible with the commercialized grade of general purpose carbon fibers even at low carbonization temperature such as $800\;{^{\circ}C}$ (the carbonization temperature in the commercial process. 1300∼$1500\;{^{\circ}C}$).