• 한국추진공학회지
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• 제13권5호
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• pp.1-6
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• 2009

로켓시스템의 에너지원으로 적용할 수 있는 기체발생기용 복합 고체추진제의 개발과정을 기술한다. 80%의 고체입자 부하율과 양호한 유동성, 그리고 $-50^{\circ}{\sim}70^{\circ}C$에서 경화에 적절한 추진제 물성을 갖는 HTPB를 바인더로 하여, 낮은 화염온도, 적은 고체입자 잔사, 무독성 생성물의 추진제 제조가 가능한 AN을 제1종 산화제로, 탄도특성 제어에 필요한 AP를 제2종 산화제로 추진제 주요 조성이 구성된다. 기본조성을 근거로 하여 일련의 물성개선 시험이 수행되었으며 최대응력 8 bar 및 최대응력점 변형율 30%, 그리고 탄성계수 1000 psi 수준의 물성을 갖는 추진제 조성을 얻을 수 있었다.

• 한국식품조리과학회지
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• 제15권3호
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• pp.224-230
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• 1999

The purpose of this study was to find out the optimal mixing ratio of green tea powder, sugar, and water for the preparation of Seolgiddeok through Response Surface Methodology based on the color, sensory, and texture test. The oganoleptic and textural properties of Seolgiddeok prepared with various concentrations of green tea powder (0% (control group), 0.5% (GT-0.5 group), 1% (GT-1.0 group), 1.5% (GT-1.5 group), 2% (GT-2.0 group)), and their quality changes during storage were also investigated. The optimal mixing ratio of green tea powder, sugar, and water for preparing the best quality Seolgiddeok was 1.0%, 12%, and 22%, respectively. The proximate composition of green tea powder was 21.70% of crude protein, 8.49% of crude lipid, 2.95% of reducing sugar, and 6.40% of ash. The contents of crude lipid, reducing sugar, and catechins in Seolgiddeok added with a green tea powder were increased with increasing the content of green tea powder. The hardness and gumminess of GT-1.0 group were the lowest among four groups, whereas GT-1.0 and GT-2.0 groups had the lowest cohesiveness. While the control group was the lowest in adhesiveness, the springness was not significantly different among all groups. GT-0.5 and GT-1.5 groups were the highest in sweet taste and colorfulness, respectively. However, GT-1.0 group had the best overall quality. Total microbial numbers, the acidity and pH in Seolgiddeok during storage were decreased with increasing green tea powder content, and especially those of GT-1.0 and GT-1.5 groups were relatively the lower than others. The “L” value (lightness) of the control group (no additives) was the highest among five groups, and the value was decreased with storage period, and especially GT-0.5 groups had the lowest brightness. The“a”value (reddness) of the control group was the highest, followed by GT-0.5, GT-1.0, GT-1.5, and GT- 2.0 group in order. The“b”value (yellowness) was increased with the increase of green tea powder content. Above results indicated that GT-1.0 group showed the best quality of Seolgiddeok through organoleptic and rheology tests.

• 한국식품조리과학회지
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• 제21권5호
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• pp.647-654
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• 2005

This study was conducted to investigate the quality characteristics of Jeung-Pyun prepared with the addition of ultrafiltered(UF) sunmul powder. Jeung-Pyun was prepared with five different levels of UF powder(0%, 0.5%, 1%, 2% and 3%) and the physico-chemical properties were examined. The pH of Jeung-Pyun batters decreased from $4.57{\sim}5.69$ to $4.38{\sim}5.03$ during 4 hours of fermentation at $35^{\circ}C$. The weight of Jeung-Pyun decreased, whereas the volume increased, with increasing UF powder content. Total isoflavone content was $0.41{\sim}2.39\;mg%$ before cooking and increased to $0.77 {\sim}3.80\;mg%$ after cooking. The increase of aglycones was particularly observed after cooking. The incorporation of UF powder in Jeung-Pyun lowered the lightness values but increased the redness and yellowness values. Rheology test showed that hardness was decreased with increasing UF powder amount. The values of gumminess and brittleness were the highest in the control group and decreased with increasing UF powder amount. Scanning electron microscope showed that the size of the air cells decreased with increasing UF powder levels. The results of sensory evaluation showed that there were no significant differences in scores of sweetness and moistness among the samples. Therefore, Jeung-Pyun prepared with UF to 3% addition of UF powder was considered to be as acceptable as Jeung-Pyun prepared without UF power.

• 한국식품영양학회지
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• 제29권6호
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• pp.1008-1014
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• 2016

This study was conducted with the purpose of investigating the rheological characteristics of noodle flour dough supplementary konjac powder comprising 0%, 0.5%, 1.0%, 1.5% or 2.0% of the total mixture. In farinograph analysis, water absorption increased with the increased content of konjac powder. Both the arrival times and the development times of the dough with added konjac powder were longer than original wheat flour dough. Dough stability was found to be increased as compared to the control, but decreased as konjac powder content was increased. As konjac powder content increased, the resistance of the dough as shown by farinograph data was highest in the original wheat flour dough as 130 BU. Starting temperature, maximum viscosity temperature and maximum viscosity were decreased as shown in amylograph analysis. In extensograph analysis, the dough's extensibility and resistance to extension of the dough decreased as the amount of konjac powder was increased. The ratio of resistance to extensibility (R/E) decreased with the an increase in the amount of konjac powder included in the dough. The dough's tensile strength after cooking was increased in proportion to the additional amount of konjac powder used.

• 폴리머
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• 제24권5호
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• pp.589-598
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• 2000

불포화 폴리에스테르(unsaturated polyester : UPE) 수지를 다가알콜 (propylene glycol : PG, neopentyl glycol : NPG)의 각 몰비를 조정하여 포화 이염기산(isophthalic acid : IPA)과 불포화 이영기산 (maleic anhydride : MA)의 혼합물로 축합반응으로 제조하였다. 고체의 표면특성을 결정짓는 임계표면장력(${\gamma}_{c}$)을 Zisman plot으로 평가하였고, 또한 수지의 구조와 물성과의 관게를 레올로지 측정으로 조사하였다. 고체 glass에 의한 (${\gamma}_{c}$)은 UPE 수지 액체들에 대해서 30.5mN${\cdot}m^{-1}$를 얻었고, PG/NPG 몰비중 NPG 함량이 증가할수록 UPE 수지 용액의 접촉각과 표면장력이 감소됨을 확인할 수 있었다. 그리고 글리콜 몰비가 다른 UPE 수지의 동적 점탄성을 측정하면 정상류 점도의 전단속도 의존성, 동적 탄성율의 각 주파수 의존성에 의해 순수한 PG보다는 NPG의 함량이 증가할수록 낮은 값을 얻을 수 있었다.

• 접착 및 계면
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• 제15권4호
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• pp.145-150
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• 2014

Dicyclopentadiene (DCPD)계 석유수지는 많은 분야에서 점착부여수지로 널리 사용되고 있다. 특히, 수소첨가 반응으로 수지 내 이중결합을 수소로 치환시킨 수첨(水添) DCPD계 석유수지는 무색투명의 색상과 빛과 열에 대한 우수한 안정성으로 인해, 고급 핫멜트접착제(hot melt adhesives, 이하 HMAs) 또는 열용융형 감압접착제(hot melt pressure sensitive adhesives, 이하 HMPSAs) 용도에 널리 사용되고 있다. 본 논문에서는 다양한 수첨 DCPD계 석유수지가 SIS와 SBS와 같은 SBCs를 기본 엘라스토머로 사용한 HMPSAs에서 점착부여수지로 사용될 때의 접착성능에 대해 논의하며, 점착부여 수지의 특성과 HMPSAs의 접착성능과의 상관관계를 보여준다. 높은 연화점의 점착부여수지를 사용할 수록 HMPSAs의 $T_g$, 연화점 그리고 crossover temperature가 높아졌다. 높은 방향족 모노머 함량의 점착부여수지를 사용할 경우에는, PSAs의 crossover temperature 및 연화점 감소로 확인할 수 있듯이 PSAs의 내열온도를 저하시키는 경향을 보였다.

• Macromolecular Research
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• 제17권2호
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• pp.110-115
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• 2009

The electrical, morphological and rheological properties of melt and dry mixed composites of poly ethylene (PE)/graphite (Gr), polypropylene (PP)/Gr and PP/nickel-coated carbon fiber (NCCF) were investigated as a function of filler type, filler content and processing temperature. The electrical conductivities of dry mixed PP/NCCF composites were increased with decreasing processing temperature. For the melt mixed PP/NCCF composites, the electrical conductivities were higher than those of the melt mixed PE/Gr and PP/Gr composites, which was attributed to the effect of the higher NCCF aspect ratio in allowing the composites to form a more conductive network in the polymer matrix than the graphite does. From the results of morphological studies, the fillers in the dry mixed PP/NCCF composites were more randomly dispersed compared to those in the melt mixed PP/NCCF composites. The increased electrical conductivities of the dry mixed composites were attributed to the more random dispersion of NCCF compared to that of the melt mixed PP/NCCF composites. The complex viscosities of the PP/Gr composites were higher than those of the PP/NCCF composites, which was attributed to the larger diameter of the graphite particles than that of the NCCF. Furthermore, the fiber orientation in the 'along the flow' direction during melt mixing was attributed to the decreased complex viscosities of the melt mixed PP/NCCF composites compared those of the melt mixed PP/Gr composites.

• Applied Biological Chemistry
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• 제41권5호
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• pp.367-371
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• 1998

호주산 표준흰밀(Australian Standard White, ASW)로 제분한 제면용 밀가루 4종의 리올로지 성질과 입도분포를 미국산 경질붉은겨울밀(Hard Red Winter, HRW)과 서부흰밀(Western White, WW)의 혼합밀로 제분한 밀가루와 비교하였다. ASW 밀가루는 미국산보다 단백질과 회분함량이 낮았고, 아밀로그래프 최고점도는 높았다. 파리노그래프 흡수율은 호주산 밀가루가 높았으나 반죽형성시간은 호주산과 미국산 사이에 차이가 없었다. 밀가루 반죽의 저항도와 신장도는 호주산 밀가루가 작았다. 밀가루 입자크기 분포는 시료마다 독특한 경향을 보였다. 파리노그래프 지표는 단백질 또는 익스텐시그래프 지표와 상관을 보이지 않았다. 아밀로그래프 최고점도는 단백질과 (-)상관을, 익스텐시그래프의 신장도는 단백질과 (+)상관을 보였다.

• 한국수산과학회지
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• 제36권6호
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• pp.716-722
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• 2003

This study determined the optimum dosage for coagulation reactions of red tide organisms (RTO) using a combination of ignited oyster shell powder (10sp) and loess and examined the electrokinetic and rheological characteristics of their flocs. Two kinds of RTO, Cylindrotheca closterium and Skeletonema costatum, were sampled in Masan Bay and cultured in the laboratory. Coagulation experiments were conducted using various concentrations of IOSP, loess, IOSP+1oess, RTO, and a jar tester RTO cell numbers were counted for both the supernatant and RTO culture solution. The removal rates increased rapidly with increasing IOSP concentrations up to 50 mg/L and loess concentrations up to 800 mg/L. A removal rate of $100\%$ was reached at 400 mg/L of IOSP and 6,400 mg/L of loess. The highest increment $(16.7\%)$ of the rates of coagulation reaction occurred using both IOSP and loess (50+200 mg/L) in comparison with IOSP alone. The rate of coagulation reaction using both IOSP and loess (50+200 mg/L), $90.6\%,$ was similar to employing either IOSP of 150 mg/L or loess of 3,200 mg/L. All of the coagulation liquids for RTO, IOSP (200 mg/L), loess (200 ma/L), and IOSP+1oess (200+200 mg/L) revealed non-Newtonian fluid properties and therefore their shear rate vs. shear stress curves were non-linear. The coagulation liquids revealed elastic body properties at a lower shear rate increasing in the following order: RTO, IOSP (200 mg/L), loess (200 mg/L), and IOSP+1oess (200+200 mg/L. IOSP+1oess (200+200 mg/L) especially demonstrated plastic flow properties at a lower shear rate.

• 동아시아식생활학회지
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• 제14권4호
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• pp.370-378
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• 2004

The purpose of this study was to investigate the effect of added nutriprotein and rice powder as a plasticizer on physicohemical property, texture property of Backsulgi. In the physicochemical property, the content of proximate composition of nutriprotein was measured as 6.1% of moisture, 3.6% of carbohydrate, 84.3% of crude protein, 0.6% of crude lipid, 5.4% of ash. The raw material of rice powder was measured as 9.6% of moisture, 83.7% of carbohydrate, 6.0% of crude protein, 0.4% of crude lipid, 0.3% of ash. Swelling power and pore ratio of the control were 78.53% and 72.42%, and tended to increase as the amounts of nutriprotein and plastic rice powder increased. Aging by Avrami eguation retarded in Backsulgi added 10% plastic rice powder than rice powder Backsulgi. All the samples added 2, 4, 6, and 8% nutriprotein at the temperatures of 20 were more effective than others on aging. In texture properties, cohesiveness and springiness were not significantly changed by adding nutriprotein and not significantly changed during the storage period in all samples. Hardness and gumminess decreased by adding 2∼8% nutriprotein and increased during the storage period in all samples. Springiness and gumminess decreased by adding 40% plastic rice powder and increased during the storage period in all sample. Cohesiveness and hardness decreased by the increase of plastic rice powder. The texture characteristics by rheometer showed that Backsulgi with nutriprotein and plastic rice powder exhibited lower in hardness than the control, indicating that nutriprotein and plastic rice powder were effective in retarding retrogradation, which is better when storage time became longer.