• 제목/요약/키워드: stability period

검색결과 1,552건 처리시간 0.03초

홍국의 황색색소 Monascin에 대한 안정성 연구 (Stability of Monascin Pigment Isolated from Monascus purpureus)

  • 박영현;채지민
    • 한국식품위생안전성학회지
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    • 제12권1호
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    • pp.15-19
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    • 1997
  • The stability of monascin yellow pigment isolated from Monascus purpureus was determined over a period of storage for the wide range of pH, various metal ions and antioxidants. The absorption maximum of monascin pigment was 385 nm. Monascin pigment was more stable in acid solutions than in alkaline (pH 9 and pH 11) during storage period. It was also observed the reduction of absorption was occur after 3 days storage. The stability of monascin pigment was not changed by adding the various metal ions of the concentration of 10-4 M, however, it was unstable by adding the Zn2+, Al3+ and Fe3+ of 103- M concentration. The antioxidants. BHA, BHT, cysteine and L-ascorbic acid, have no effects on the stability of monascin yellow pigment. Thus, it may be concluded that the monascin pigment is stable and useful food additives as the natural colorant except for the alkaline food and food containing the Zn2+, Al3+ and Fe3+.

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수치해석을 통한 제방 구조물의 내진 안정성에 관한 연구 (A Study on Seismic Stability of Embankment Structure by Numerical Modeling)

  • 신은철;이승택;강현회;류병현
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 추계 학술발표회 2차
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    • pp.186-191
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    • 2010
  • Recently, it has been reported that number of earthquakes was rapidly increased in the Korean Peninsula. According to the interest of seismic analysis, most of construction design must ensure the stability of structure against risks due to earthquake. Therefore, the ground reinforcement and application of seismic standards is necessary and the new structures must secure a stability about Earthquake under the Korea Seismic Analysis Standards. In this study, the 2D numerical analysis was performed to confirm a seismic stability and analysed that behavior of ground and dykes. The numerical seismic response analyses for dykes and its foundation soil were conducted with considering earthquake modes of short-period and long-period, and artificial seismic wave.

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Resonance Frequency Analysis(RFA)를 이용한 임플란트 종류간의 초기 안정성 비교 (Comparison of initial implant stability measured by Resonance Frequency Analysis between different implant systems)

  • 오준호;장문택
    • Journal of Periodontal and Implant Science
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    • 제38권3호
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    • pp.529-534
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    • 2008
  • Purpose: The objective of this study was to compare initial implant stability measured by RFA between different implant systems during the initial healing period. Material and Methods: Fifty-four patients (36 males/18 females) who had been treated at the Department of Periodontology, Chonbuk National University Dental Hospital during the period between January and November in 2007 were included in the study. The mean age of the subjects was 49 years old (18 to 77). A total of 104 implants (Type A: 3i $Osseotite^{(R)}$, Type B: $Replace^{(R)}$ select, Type C: ITI implant) were placed following the manufacturer's standard surgical protocols. Implant stability quotient (ISQ) readings were obtained for each implant at the time of surgery, 2-, and 4-month postoperatively. Result: No implant was failed during the observation period. At the baseline, the difference between mean ISQ values of 3 implant systems was statistically significant (p<0.05). However, at 2-, and 4-month following implant surgery, no significant difference was observed between ISQ values of the implant systems. In the same implant, the ISQ values of Type B and C implants increased (p<0.05), but those of Type A implants decreased during the 2-month healing period. The mean ISQ values of Type B and C implants showed a increasing tendency, while those of Type A implants were stable for the 4-month follow-up period. Conclusion: Within limits of this study, it can be concluded that implant design and surface topography of implant might influence the ISQ value and changing pattern during the initial healing period.

Resonance frequency analysis를 이용한 non-submerged type 임플란트의 초기 안정성 분석 (Non-submerged type implant stability analysis during initial healing period by resonance frequency analysis)

  • 김득한;방은경;김창성;최성호;조규성
    • Journal of Periodontal and Implant Science
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    • 제39권3호
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    • pp.339-348
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    • 2009
  • Purpose: The purpose of the present study was to analyze the implant stability quotient(ISQ) values for Korean non-submerged type implant and determine the factors that affect implant stability. Methods: A total of 49 Korean non-submerged type implants were installed in 24 patients, and their stability was measured by resonance frequency analysis(RFA) at the time of surgery, and 1, 2, 3, 4, 8, 12 weeks postoperatively. The data for implant site, age, sex, implant length and diameter, graft performing, bone type, and insertion torque were analyzed. Results: The lowest mean stability measurement was at 3 weeks. There was significant difference between implant placement and 12 weeks. There was significant difference between implant placement and 12 weeks in diameters of 4.1 mm and 4.8 mm. Also, there were significant differences between diameters of 4.1 mm and 4.8 mm at implant placement and 12 weeks after surgery. This result suggests that the factor related to implant diameter may affect the level of implant stability. No statistically significant relationship was found between the resonance frequency analysis and the variables of maxilla/mandible, sex, anterior/posterior, implant length, age of patient, graft performing, bone type, insertion torque during initial healing period. Conclusions: These findings suggest that the factor related to implant diameter may affect the variance of implant stability, and ISQ value of implant was stable enough for proved stability level during initial healing period.

생활계 폐합성수지 물질 재활용 제품의 생산시기별 품질 특성 (Quality Characteristics According to the Production Period of Products Obtained by Recycling Household Plastic Waste Materials)

  • 강혜주;신성철;강석표
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 가을 학술논문 발표대회
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    • pp.167-168
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    • 2020
  • In order to expand the material recycling of waste plastics made of composite materials, it is necessary to develop the use of material recycling products and to secure their quality stability. In this paper, as a basic study to secure the stability of the quality of household waste plastic material recycling products, the quality characteristics of recycled materials according to the production period were compared and reviewed. In addition, the average tensile strength of the recycled products by production period for 4 months was 12.33 MPa, and the average density was 1.35 g/m3.

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유아의 친구관계 안정성에 대한 단기 종단적 탐색 (Stability in Friendship Patterns Among Kindergarteners: A Short-Term Longitudinal Study)

  • 박미현;박경자
    • 아동학회지
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    • 제37권1호
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    • pp.73-82
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    • 2016
  • Objective: This two-wave study examined stability in kindergarteners' friendship patterns over 5 months. Methods: Participants were 501 five-year-old children (262 girls and 239 boys) attending kindergartens in Seoul, Incheon, and Kyounggi provinces in Korea. Each child nominated three individuals as his/her friends in July, and again in December of 2013. Depending on the presence/absence of friendships and the mutuality of identifying friends, the children's friendship patterns were categorized into five groups: stable, fluid, loss, gain, and friendless. The data were analyzed by descriptive statistics, and chi-square tests. Results: Results revealed stability, as well as changes in friendship patterns, among kindergarteners over the 5-month period. The stable friendships, those that maintained the same friend(s) in both waves, was 43.7%, the fluid friendships, those that changed friends over the 5 month period was 18%, the gain friendships, those who had newly developed friends in wave 2 was 17%, and the loss friendships, those who had friends at wave 1 but lost friends at wave 2, was 9.8%. The friendless, those that had no friends in both waves, was 11.5%. Conclusion: Results showed that kindergarteners were capable of maintaining and making new friends over a 5-month period.

초임계 이산화탄소 처리된 저지방 대두분말로 제조한 식물성 대체육의 이화학적 품질 특성 및 저장 안정성 (Physicochemical Properties and Storage Stability of Plant-based Alternative Meat Products Prepared with Low-Fat Soybean Powder Treated by Supercritical CO2)

  • 표민정;이교연;한채연;박채은;최성길
    • 한국식품영양학회지
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    • 제36권4호
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    • pp.264-273
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    • 2023
  • Physicochemical properties and storage stability of plant-based alternative meat prepared with low-fat soybean powder (LPAM) treated by supercritical-CO2 and those of full-fat soybean powder (FPAM) were compared. Ash and crude protein contents were higher in LPAM than in FRAM. Water absorption capacity and oil absorption capacity were significantly higher in LPAM than in FPAM. Water binding capacity was higher in LPAM than in FPAM during a 20 days storage period at 5℃ and pH was significantly lower in LPAM than in FPAM after a 5~10 days storage period. Hardness, gumminess and chewiness significantly increased with the increase in the storage period, and the three were significantly higher in LPAM than in FPAM after 10 days and 20 days of storage. The acid value showed no remarkable difference according to the storage period in LPAM; however, it was significantly higher in FPAM than in LPAM after 20 days of storage. The peroxide value and TBA value were significantly increased according to the storage period, and were significantly lower iin LPAM than in FPAM during all the storage periods. Therefore, the use of low-fat soybean powder may be effective in improving oxidative stability during storage in the production of plant-based alternative meat.

스파 플랫폼의 Mathieu형 불안정성에 미치는 감쇠판의 영향 (The Effect of Damping Plate on Mathieu-type Instability of Spar Platform)

  • 노준범;최항순
    • 대한조선학회논문집
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    • 제42권2호
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    • pp.124-128
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    • 2005
  • This paper describes motion stability of a spar platform with and without a damping plate in regular waves. The heave and pitch motion equation is derived in terms of Mathieu equation and the stability diagram is obtained. It is shown that the spar platform with damping plate has smaller unstable region than that without damping plate in the stability diagram. Model tests are carried out to verify the mathematical analysis. Under the condition that the pitch natural period is approximately double the heave natural period and the heave motion is amplified at heave resonance, unstable pitch motions are evoked. However the unstable motion is stabilized in cases of spar platform with damping plate. Therefore the damping plate is an effective device to stabilize the motion of spar platform.

건강기능식품 원료로서 작약감초복합추출물(EGHB010)의 안정성 평가 (Evaluation of Stability in a Combined Extract of Paeoniae Radix and Glycyrrhizae Radix(EGHB010) as a Health Functional Food)

  • 이기만;김현종
    • 생약학회지
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    • 제50권4호
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    • pp.318-323
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    • 2019
  • This study was designed to establish the stability of EGHB010, a combined hot water extract of Paeoniae Radix and Glycyrrhizae Radix. Test of coliform groups, sensory evaluations, contents of moisture, and the amount of paeoniflorin and glycyrrhizin were determined during storage at 4, 25 and 35℃ for 6 months. Coliform groups were not observed and moisture contents were maintained about 3.0% during the storage period. Sensory characteristics including color, taste, texture and appearance were tested over 3 points throughout the entire storage period. It maintained the commercial value during the storage period. Contents of paeoniflorin and glycyrrhizin as indicator components were remained stably for the storage period. The shelf-life of EGHB010 based on a linear response to zero of sensory evaluation with the highest correlation coefficient was predicted. Finally, the shelf-life of EGHB010 was expected for about 3 years to consider in safety coefficient. The shelf-life data of EGHB010 can be used to develop a functional health ingredient.