• 한국추진공학회지
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• 제24권2호
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• pp.14-27
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• 2020

본 연구는 점화제와 지연제에 대한 시차 주사 열량 측정법을 통하여 반응 속도식 및 발열량을 추출하여 노화에 따른 반응 특성을 분석하기 위한 정밀 수치계산을 수행하였다. 연소 실험을 수행하여 수분이 관여된 노화에서 점화제와 지연제에서 명확한 연소 중단을 확인하였다. 이 결과를 수치계산과 비교하여 노화가 점화제와 지연제 전반에 성능 감소 및 오작동 요인으로 작용됨을 확인하였다.

• 약학회지
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• 제38권3호
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• pp.300-310
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• 1994

Physicochemical properties for the inclusion complex of chenodeoxycholic acid(CDCA) and it's $7{\beta}-hydroxy$ epimer ursodeoxycholic acid(UDCA) with ${\beta}-cyclodextrin({\beta}-CyD)$ were studied. The formation of the complex in the solid state were confimed by polarized microscopy and differential scanning calorimetry(DSC). Proton nuclear magnetic resonance$(^1H-NMR)$spectroscopy showed that CDCA and UDCA form an inclusion complex with ${\beta}-CyD$ in aqueous solution. The 1 : 1 stoichiometry of the complex was dextermined by the continuous variation method. From DSC and $^1H-NMR$ studies, there were not any differences between CDCA and UDCA. Complex of CDCA and UDCA showed increase in solubility and dissolution compared with CDCA and UDCA alone, respectively. Solubility pattern of UDCA complex was pH independent but, CDCA complex was like that of CDCA. Dissolution rate increased markedly in case of UDCA complex compared with CDCA complex, especially in acidic pH value.

• 한국응용과학기술학회지
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• 제24권4호
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• pp.416-426
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• 2007

Polypropylene (PP) composites with wood flour/wax/coupling agent were manufactured by melt compounding and injection molding. The influence of wood flour(WF), wax, and coupling agent on the mechanical and thermal properties of the composites was investigated. The addition of wood flour to neat PP has the higher tensile modulus and strength compared with neat PP. The presence of wax also improved the tensile modulus. At the same loading of PP and WF, the addition of coupling agent highly decreased the tensile modulus, and increased the tensile strength. From thermogravimetric analysis (TGA), the addition of wax improved the thermal stability of the composites in the later stages of degradation. The presence of MAPP and wood flour in turn decreased thermal stabilities of composites. From differential scanning calorimetry analysis (DSC), neither the loading of wax. nor the presence of MAPP has shown significant effect on the thermal transition of composites.

• Journal of Nutrition and Health
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• 제22권6호
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• pp.423-437
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• 1989

A 4-week energy balance study was conducted to estimate the energy expenditure (EE) of 16 college age men and women, 20 to 26 year of age, by measurement of energy intakes and changes in body energy(BE) content(intake/balance technique), keeping their normal living pattern and maintenance body weight. Energy intake was measured by bomb calorimetry and estimated by food table. Fecal energy loss was calculated from nitrogen excreted. Fat mass was determined from body density estimated from skinfold tickness. 1) Gross energy (GE) intakes calculated from food table was not only 13.4% lower than those of bomb calorimetry but also lower 4 and 5% than metabolizable energy(ME) intakes for the male and female subjects, respectively. 2) Fecal energy loss was 7.2% and 6.9% proportion of the gross energy intake for the male and female subjects, respectively. 3) Mean daily metabolizable energy intakes estimated by subtract fecal and urinary energy loss was 2467kcal for the male subjects and 1897kcal for the female subjects. 4) Total body energy change estimated from body composition change over 31 days was decreased 7672kcal for the male subjects and 2689kcal for the female subjects. 5) Mean daily energy expenditure was 2714kcal (45kcal/kg of body weight) for the male subjects and 1984kcal(40kcal/kg of body weight) for the female subjects. 6) The estimated energy expenditure of college-age subjects in this study provide evidence to support the Recommended Dietary Allowances for energy of Korean normal adult.

• Composites Research
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• 제14권2호
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• pp.33-42
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• 2001

DSC(differential scanning calorimetry)를 이용하여 S2-유리섬유/폴리에스터 프리프레그 복합재료의 경화반응식을 구성하였다. 구성된 경화식과 블리더의 수지 함침에 의한 열전달 조건의 변화를 고려하여, 두꺼운 복합재료의 두께 방향 위치에 따른 온도분포를 계산하였다. 유래섬유 복합재료의 경화중 온도과승을 줄이기 위한 방법으로 냉각 및 재가열 구간을 도입하여 경화 사이클을 개선하였다. 냉각-재가열 구간이 없는 기존의 경화 사이클과 개선된 경화 사이클로 두꺼운 복합재료를 각각 제조하여 short beam shear 시험 및 Barcol 경도시험을 실시하고, 그 결과를 비교하였다.

• 한국식품영양학회지
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• 제20권2호
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• pp.185-194
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• 2007

This study was performed to evaluate the physicochemical, sensory evaluation of Backsulgi changed with germinated brown rice flour(GBRF) at different ratio. Moisture content decreased gently during storage and the decrease was less in GBRF-added groups than the control group. The color L value decreased significantly by with increasing the GBRF, wherease the redness(a) and yellowness(b) were both increased. As the result of measurement with texture analyzer, hardness, gumminess, chewiness, adhesiveness and fracturability of Backsulgi tended to decrease in proportion to the amount of GBRF in the formula. The thermal properties of Backsulgi were investigated by differential scanning calorimetry(DSC). Onset temperature and peak temperature of gelatinizatino in thermal characteristics showed low in case of addition of GBRF into Backsulgi. All samples changed with GBRF had low values in change of melting enthalphy. In the sensory evaluation, Backsulgi with GBRF were superior in flavor, cohesiveness, hardness, chewiness and moistureness than that of control. And Backsulgi with 20% GBRF showed the highest score in overall acceptability. Therefore we concluded that the addition of GBRF on Backsulgi improve the sensory characteristics as well as delay the retrogradation.

• 한국식품과학회지
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• 제30권1호
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• pp.237-240
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• 1998

새로운 저열량 감미료인 tagatose를 이용한 초콜렛을 제조하여 설탕으로 제조한 초콜렛과 물성을 비교하였다. 제조한 초콜렛의 물성을 Casson 식에 적용한 결과 tagatose를 첨가하여 만든 초콜렛의 consistency index는 1,070 cp이었고 yield stress는 3.4 Pa으로 설탕을 사용한 초콜렛과 유사한 점도 특성을 보였다. Tagatose를 첨가하여 제조한 초콜렛을 DSC를 사용하여 열 특성을 살펴본 결과 설탕을 사용한 초콜렛과 유사하였다. 두 초콜렛의 점성 특성과 열 특성은 유사하였으나 강도의 경우는 tagatose를 사용한 제품의 강도가 설탕으로 만든 초콜렛의 강도보다 떨어짐을 보여주었다.

• 한국세라믹학회지
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• 제39권7호
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• pp.617-621
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• 2002

Calcium aluminosulfate (3CaO.3Al$_2$O$_3$.CaSO$_4$or $C_4$A$_3$S) was prepared by chemical synthesis from the nitrate salts and aluminum sulfate. $C_4$A$_3$S was the main phase after calcination at 110$0^{\circ}C$. The specific surface areas after calcination at 110$0^{\circ}C$ and 130$0^{\circ}C$ were about 2.5 and 1.0 $m^2$/g, respectively. Hydration was investigated by XRD, DSC, SEM, EDS, conduction calorimetry and analysis of the liquid phase. Calorimetry showed that the induction period was longer than that of a sample prepared by conventional solid state sintering and this was attributed to the formation of amorphous coatings in abundance of $Al_2$O$_3$ and SO$_3$. Crystalline hydration products, principally calcium monosulfoaluminate hydrate and Al(OH)$_3$, appeared subsequently.

• Journal of Pharmaceutical Investigation
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• 제29권4호
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• pp.309-313
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• 1999

This study was prepared to develop the sustained release dosage form of phenylpropanolamine hydrochloride (PPA) by complexation with cation exchange resin(CER). The PPA-CER complex was confirmed by differential scanning calorimetry(DSC) thennogram, indicating a relative shift of an endometric peak of PPA to higher temperature. The loading efficiency was increased as the amount of PPA was increased as well as the time of fractional exchange was advanced as the temperatures were increased. Loading efficiency, fractional exchange, reaction rate constant and activation energy were highly dependent on the temperature and drug : resin ratio. The optimal ratio of PPA and resin was estimated to be 10: 10 for the sustained release.

• Archives of Pharmacal Research
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• 제23권4호
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• pp.381-384
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• 2000

It is well recognized that physicochemical properties of drugs are affected by the type of polymorphic crystalline form of drugs. Clarithromycin is known to exist in at least three polymorphic crystalline forms. Since conventional means to obtain the most thermodynamically stable form (Form II) for the antibiotics is known to be associated with a low purity of the stable form, we developed a novel method to improve the purity of the crystalline form by a modification of the preparation process. The new method involved a simple recrystallization of clarithromycin in solvents having 5-12 carbon atoms (e.g., hexane and heptane) or ethers with 4-10 carbon atoms (e.g., isopropyl ether) and, thus, less likely to be associated with the problem in purity of resulting crystal. Differential scanning calorimetry and powder X-ray diffraction were used to compare the crystalline form of the resultant powder with Form IIcrystal prepared by the conventional method. The crystal prepared by the new method was identical to Form IIcrystal of the conventional method as evidenced by the lack of the exothermic peak near 11$0^{\circ}C$ in differential calorimetry scan, indicating that Form IIcrystal could be readily prepared by the new process. Therefore, these data indicated that the improvement in the purity of the Form IIcrystal for clarithromycin as well as a significant cost reduction is likely by the novel method.