• 접착 및 계면
• /
• 제10권2호
• /
• pp.106-112
• /
• 2009

본 연구에서 처음으로 생분해성 라이오셀 직물과 poly(butylene succinate) (PBS)로 이루어진 바이오복합재료가 성공적으로 제조되었다. 0, 30, 40, 50 그리고 60 wt%의 서로 다른 함량의 라이오셀직물을 포함하는 라이오셀/poly(butylene succinate) 바이오복합재료는 sheet interleaving 방식으로 압축성형에 의해 제조되었다. 바이오복합재료의 층간전단강도, 인장 및 굴곡 특성, 열변형 온도, 열팽창 거동 및 열안정성에 미치는 라이오셀직물 함량의 영향을 조사하였다. 특성들은 직물함량에 크게 의존하였으며, 그 결과들은 서로 일치하였다. 라이오셀직물을 수지에 도입하는 것이 poly(butylene succinate)의 여러 가지 특성 향상에 두드러진 역할을 하는 것으로 확인되었다. 라이오셀직물이 중량비로 50%일 때, 바이오복합재료의 가장 우수한 층간전단강도, 인장, 굴곡 및 열적 특성이 얻어졌다.

• 한국해양공학회지
• /
• 제21권3호
• /
• pp.46-51
• /
• 2007

A multi-purpose environmental monitoring system has been developed as a commercially available standard using the technique of hetero-core spliced fiber optic sensors, for the purposes of monitoring large-scale structures and preserving natural environments. The monitoring system has been tested and evaluated in a possible outdoor condition, in view of the full-scale operation at actual sites to be monitored. Additionally, the developed system in this work conveniently provides us with various options of sensor modules intended for monitoring such physical quantities as displacement, distortion, pressure, binary states, and liquid adhesion. Two channels of optical fiber line were monitored in each channel, three displacement sensor modules were connected in series, in order to examine the performance to a pseudo-cracking experiment in the outdoor situation and to clarify temperature influences an the system, in terms of the coupling of optical connectors and the OTDR stability. The results from the pseudo-cracking experiment agreed with the actual cracks, by means of calculation, based an the detected displacement values and their geometrical arrangement of the used sensor modules. The temperature change, ranging from 10 to $20^{\circ}C$ resulting from the 10-days free running operation, was found to influence the system stability of ${\pm}10{\mu}m$, primarily due to the coupling instability of the used optical connectors. It was found that fusion splicing, rather than the use of connectors, reduced the fluctuation dawn to ${\pm}2{\mu}m$. The specification and performance of various option modules have been demonstrated to show the capability of inspecting various physical quantities by use of the single system, which would be suitable for multi-purpose environmental monitoring.

• 기술사
• /
• 제17권4호
• /
• pp.8-14
• /
• 1984

In this part of the studies on dielectric dehydration of foamed fish-starch paste, quality stability and shelflife of the product of which the preparation formula and processing conditions were described in the previous report (Lee et at., 1982) were determined by means of accelerated reaction test. The product was stored for 50 days under the conditions of temperatures at 35, 45, and 55$^{\circ}C$ in steady state and various water activities of 0.44, 0.52, 0.65, and 0.75, respectively. The loss of available lysine, the extent of TBA value, and the development of browning during the storage were measured and reaction kinetically analysed to assess quality stability and shelf-life of the product for the storage at room temperature of 25$^{\circ}C$. The extent of browning was accelerated with the increase of water activity and temperature marking the time to reach a limit of color and flavor deterioration, or to reach brown color density of 0.17 O.D./g at 420nm, 106 days at a$\_$w/=0.44, 35$^{\circ}C$, and 41 days at aw=0.65, 55$^{\circ}C$. These reaction rates resulted in a prediction of shelf-life, 130 to 110 days in the storage at au=0.44 to 0.75, 25$^{\circ}C$. The quality limit assessed by TBA values and sensory evaluation of rancidity was 87 days at a$\_$w/=0.44, 35$^{\circ}C$, and 30 days at aw=0.73, 55$^{\circ}C$ which gave a predicted shelf-life, 128 to 113 days at a$\_$w/=0.44 to 0.75, 25$^{\circ}C$ storage.

• 한국식품영양과학회지
• /
• 제28권5호
• /
• pp.1034-1043
• /
• 1999

Rheological properties of dough made from waxy barley(Iri28) flour wheat flour mixtures with additives were investigated for the preparation of waxy barley bread using farinograph, extensograph and amy lograph. The water absorption, development time and dough weakness increased as the waxy barley flour level increased in all blends; however, dough stability decreased. Farinogram properties of 10% waxy barley flour added mixture were similar to those of 100% wheat flour. The addition of A.A(ascorbic acid), gluten, HPMC(hydroxy propyl methyl cellulose) improved rheological properties of dough with 30% waxy barley flour added mixture. In particular, stability and weakness of the dough showed greater dough improving effect by addition of A.A. For the extensograph data, strength, resistance and extensibility of dough decreased with increasing level of waxy barley flour. With the addition of additives, extensogram properties were variable for 30% waxy barley flour mixture. Of these additives, gluten had highest value in strength of dough. Addition of A.A and HPMC to 30% waxy barley flour added mixture resulted in an increase in the resistance and a decrease in the extensibility. Waxy barley flour added mixtures showed little higher gelatinization temperature on amylograph data than control. Maximum viscosity reduced as the waxy barley flour level increased. Also 30% waxy barley flour added mixture containing A.A and HPMC showed a decrease in maximum viscosity. But addition of gluten to 30% waxy barley flour mixture resulted an increase in the maximum viscosity. All of 30% waxy barley flour added mixture with additives had lower gelatinization temperature than those without additives. In the SEM images, starch granules were dispersed in a protein matrix. A non continuous, loose protein starch matrix was observed in all waxy barley flour mixture by SEM. Addition of additives gave the dough a more continuous structure with interactions between the starch granule and protein component.

• 한국식품조리과학회지
• /
• 제19권4호
• /
• pp.511-520
• /
• 2003

This study was carried out to determine the effects of various contents of kiwifruit contents on the quality characteristics of mixed polysaccharide gels made from $\kappa$-carrageenan and locust bean gum. The color value, gelling temperature, melting temperature, break down rate, syneresis, rupture properties, TPA properties and sensory properties of mixed polysaccharide gels with various contents of kiwifruit contents were measured. As the kiwifruit contents was increased, the lightness (L), yellowness (b) and greenness (-a) of the mixed polysaccharide gels increased. There were no differences in the color values of gels during storage. As the kiwifruit content was increased, the gelling and melting temperatures of the mixed polysaccharide gels also increased. The mixed polysaccharide gels with high kiwifruit contents were difficult to melt, and it seemed that the addition of kiwifruit to the mixed polysaccharide gels could improve the thennal stability of the gels. The syneresis of the gel increased with increasing storage time, whereas the addition of kiwifruit to the gel resulted in suppression of syneresis. With regard to the rupture properties, stress, energy and strain, they were all decreased with increasing kiwifruit contents. The TPA properties, adhesiveness, hardness and chewiness increased and cohesiveness decreased with increasing kiwifruit contents. The results showed that the gel became tough and adhesive, and could be easily broken under small deformation, with increasing kiwifruit contents. The sensory evaluation showed that the green color, aroma, sweetness and sourness increased with increasing kiwifruit contents. The texture, adhesiveness, springiness and cohesiveness decreased, and brittleness and hardness increased, with increasing kiwifruit contents. The overall acceptability of the gel with 30% kiwifruit content was the highest. Thus, mixed polysaccharide gels made from kiwifruits could be useful, as the addition of kiwifruit to a mixed polysaccharide gel results in a good aroma, taste and stability, despite a lowering of the textural properties.

• 한국식품위생안전성학회지
• /
• 제20권4호
• /
• pp.225-231
• /
• 2005

HPLC를 이용하여 국내유통 비타민보충용제품 16종에 대한 비타민 $B_{2}$ 저장조건별(기간, 차광유무, 온도)경시변화를 제형별로 분석하여 비타민 $B_{2}$ 함량면화를 검토하였다. 저장조건(저장기간, 차광유무, 저장온도)를 달리한 결과 비타민 $B_{2}$ 함량은 저장기간이 길어질수록 감소율이 크게 나타났으며 특히 저장을 시작한 처음 5개월 이전에는 비타민 $B_{2}$ 경시변화가 심하고 그 이후에는 점차 작은 변화를 보였다. 차광유무에 따른 경시변화를 보면 차광한 제품이 비차광한 제품보다 높은 안정성을 보였다. 온도별 안정성을 보면 냉장($4^{\circ}C$), 냉동($-9^{\circ}C$), 실온($30^{\circ}C$)순으로 감소율이 커졌으나 제형별로 영향을 많이 받지 않았다. 따라서 비타민B2는 온도보다는 빛에 더 불안정한 것으로 나타났다. 제형별로는 약간의 차이는 있으나 정제제품이 각 조건에서 타 제형보다 경시변화가 적어 안정성이 높은 것으로 나타났고 캅셀, 분발, 액상 순으로 액상제품이 가장 큰 경시변화를 보였다, 비타민보충용제품 제조시에는 유통과정 중 제형별, 저장기간, 차광유무 등 저장조건에 따른 경시변화결과를 비타민B2 함유제품의 유통기한 설정에 활용하는 것이 요망된다.

• 분석과학
• /
• 제25권6호
• /
• pp.483-491
• /
• 2012

본 연구는 재조합 단백질 A를 생산하기 위한 정제공정 즉, 생산공정은 양이온교환칼럼(SP)과 음이온교환칼럼(Q)을 통하여 정제한 후 최종 재조합 단백질 A를 생산하게 되는데, 공정단계별로 생산된 시료를 바로 다음단계 공정으로 가지 못하는 경우 보관을 하는데 있어 안정성 확보 문제를 가지고 있다. 이에 본 연구에서 생산공정에서 생산된 시료를 보관 했을때 적정 보관조건과 시간을 알아보고자 하는데 목적이 있다. 즉, 공정시료의 저장방법 및 저장기간 설정과 경시변화에 따른 품질의 안정성의 평가를 목적으로 한다. 실험항목은 엔도톡신, SDS PAGE, HPLC 순도 그리고 농도이다. 실험결과 양이온교환칼럼 통과 후 냉장($4^{\circ}C$), 실온보관에서 SDS PAGE는 major band, 엔도톡신은 5.0 Eu/mg이하, 농도에서는 평균 8.21~8.24 mg/mL, RSD% 0.10~0.62%, 그리고 HPLC 순도 214 nm에서 평균 99.24~99.37%, RSD% 0.22~0.29%, 280 nm에서 평균 89.72~89.80%, RSD% 0.62~1.26%로서 다소 안정된 결과를 나타내었다. 음이온칼럼통과 후 냉장($4^{\circ}C$), 실온보관에서 SDS PAGE major band, 엔도톡신 0.5 Eu/mg이하, 농도는 평균 5.59 mg/mL, RSD% 0.03~0.10% 그리고 HPLC 순도 214 nm에서 평균 99.74%, RSD% 0.10~0.11%, 280 nm에서 평균 96.16~96.85%, RSD% 0.72~1.13%의 결과를 보였다. 상기의 실험결과로 재조합 단백질 A 제조공정시료의 실온과 $4^{\circ}C$에서 7~8 일 그리고 20~21 일 보관은 물질분해 특성이 없이 안정성이 확보 되었다는 결론을 얻을 수 있었다.

• 대한본초학회지
• /
• 제32권4호
• /
• pp.25-32
• /
• 2017

Objectives : Chungsimyeonja-eum (CSYJE; Qingxinlianzi-yin in Chinese; Seishinrenshi-in in Japanese), a traditional herbal medicine, has been used for treating mouth dryness, hyperuresis. This study was designed to determine preservation period of CSYJE. We investigated the stability and biological activity of CSYJE depending on the preservation temperature and periods. Methods : CSYJE decoction was preserved for 0-6 or 12 months at room temperature (RT, $23{\pm}1^{\circ}C$) or refrigeration ($4^{\circ}C$). To evaluate the stability of CSYJE decoction, pH and dissolved solids content were measured. High-performance liquid chromatography (HPLC) analysis was performed to determine marker compounds-liquiritin apioside, liquiritin, baicalin, wogonoside, and glycyrrhizin-in CSYJE. To determine anti-inflammatory effect of CSYJE, prostaglandin $E_2$ ($PGE_2$) was measured in LPS-stimulated RAW 264.7 macrophages. Results : Both at RT and $4^{\circ}C$, pH was decreased depending on the preservation periods. There was no changes in dissolved solids content depending on the preservation temperature and periods. Both at RT and $4^{\circ}C$, the contents of liquiritin apioside and liquiritin were slightly increased at 1 month of storage. The level of baicalin was decreased time-dependently and the disappearance rate at RT is larger than at $4^{\circ}C$. CSYJE inhibited $PGE_2$ production in LPS-stimulated RAW 264.7 cells and maintained inhibitory effect by 12 months both at RT and $4^{\circ}C$. Conclusions : Based on the disappearance rate of the baicalin in CSYJE, the preservation period is recommended within 8 months for RT and 12 months for $4^{\circ}C$.

• 한국식품영양과학회지
• /
• 제33권4호
• /
• pp.711-715
• /
• 2004

홍국균이 생산하는 색소를 상업적으로 이용하기 위한 기초연구로서 Monascus purpureus CBS 281.34 80% ethanol 가용성 색소의 열 pH, 유기산 존재 시의 안정성을 알아보았다. 또한 ethanol 가용성 색소 추출물에 증류수를 가해 수분 함량이 0∼80%가 되도록 하고 수용성 색소와 함께 저장하면서 이들의 안정성도 검토하였다. 80% ethanol 가용성 홍국색소는 1$0^{\circ}C$의 저온에서 4주간 저장 시 9.74%의 분해율을 보였으나, 60∼8$0^{\circ}C$의 고온에서는 24시간과 12시간 저장 시 각각 23.06%와 30.36%나 분해되어 색소의 안정성은 단기간 내 크게 저하하였다. pH 2와 pH 10에서의 80% ethanol 가용성 색소 분해율은 pH 4∼8보다 높았고, 0.6% citric acid, 6% acetic acid 및 1.5% lactic acid를 가해 pH 4로 조정하여 4주간 저장 시에는 대조구와 대조구와의 차이가 가장 큰 acetic acid 하에서의 분해율과의 차이도 6.08%로 거의 나타나지 않아 80% ethanol 가용성 홍국 색소는 유기산하에서 비교적 안정한 것으로 사료되었다. 또한 ethanol 가용성 색소에 증류수를 가해 저장하면 색소 안정성은 저하하였는데, 색소 분해율은 수분함량 20%에서 가장 높았고 80%에서 가장 낮았다. 한편 수중에서의 ethanol 가용성 색소는 2$0^{\circ}C$보다 1$0^{\circ}C$에서 현저하게 안정하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 추계학술대회 논문집
• /
• pp.547-550
• /
• 2000

The (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics were fabricated by the conventional mixed oxide method. The sintering temperature and time were 125$0^{\circ}C$~135$0^{\circ}C$, 2hr., respectively. From the X-ray diffraction patterns, it was found that the perovskite SrTiO$_3$ and ilmenite MgTiO$_3$ structures coexisted in the (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics. The dielectric constant($\varepsilon$$_{r}$) was increased with addition of SrTiO$_3$. The temperature coefficient of resonant frequency($\tau$$_{f}$) was gradually varied from negative value to the positive value with increasing the SrTiO$_3$. The negative temperature coefficient of resonant frequency of the magnesium titanate was adjusted to near zero at x=0.036, where the dielectric constant, quality factor, and $\tau$$_{f}$ were 20.65, 95120, and +1.3ppm/$^{\circ}C$, respectively. The temperature stability of qualify factor in (1-x)MgTiO$_3$-xSrTiO$_3$(x=0.03~0.04) ceramics increased as the amount of MgTiO$_3$./TEX>.