• 제목/요약/키워드: Succinate

검색결과 397건 처리시간 0.03초

Structural Changes of Biodegradable Poly(tetramethylene succinate) on Hydrolysis

  • Shin, Jick-Soo;Yoo, Eui-Sang;Im, Seung-Soon;Song, Hyun-Hoon
    • Macromolecular Research
    • /
    • 제9권4호
    • /
    • pp.210-219
    • /
    • 2001

  • Quenched and slow cooled as well as isothermally crystallized poly(tetramethylene succinate)(PTMS) films at two different temperatures were prepared. In the process of hydrolysis of the four specimens, structural changes such as the crystallinity, crystal size distribution, lattice parameter, lamellar thickness, long period and surface morphology were investigated by using wide and small angle X-ray scattering (WAXS and SAXS), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The hydrolytic degradation of quenched film was faster than that of slow cooled and isothermally crystallized films. The film crystallized at 100$\^{C}$ exhibited extensive micro voids and thus showed faster degradation than that crystallized at 75$\^{C}$, demonstrating surface morphology is another important factor to govern degradation rate. The crystallinity of the specimen increased by 5-10% and long period decreased after hydrolysis for 20 days. At the initial stage of degradation, the lamellar thickness of quenched film rather increased, while that of slow cooled and isothermally crystallized films decreased. The hydrolytic degradation preferentially occurred in the amorphous region. The hydrolytic degradation in crystal lamellae are mainly at the crystal surfaces.

  • PDF

생분해되는 다양한 킬레이트들이 납에 노출된 식물의 성장에 미치는 영향 (Effect of Various Biodegradable Chelating Agents on Growth of Plants under Lead stress)

  • 이상만
    • 한국환경농학회지
    • /
    • 제29권1호
    • /
    • pp.61-65
    • /
    • 2010

  • Phytoextraction is a method of phytoremediation using plants to remediate metal-contaminated soils. Recently, various chelating agents were used in this method to increase the bioavailability of metals in soils. Even though phytoextraction is an economic and environment-friendly method, this cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. This research focuses on identifying chelating agents which are biodegradable and applicable to highly metal-contaminated areas. Lead (Pb) as a target metal and cysteine (Cys), histidine (His), citrate, malate, oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Ethylenediamine tetraacetic acid (EDTA) was used as a comparative standard. Plants were grown on agar media containing various chelating agents with Pb to analyze the effect on root growth. Cys strongly increased the inhibitory effect of Pb on root growth of plants, while, His did not affect on it significantly. The inhibitory effect of oxalate is weak, and malate, citrate, and succinate did not show significant effects. Both EDTA and EDA diminished the inhibitory effect of Pb on root growth. The effect of EDA is correlated with decreased Pb uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for highly Pb-contaminated area.

  • https://doi.org/10.5338/KJEA.2010.29.1.061 인용 PDF KSCI

수중 침지식 생분해성 PBSAT 그물 열처리기 개발과 성능 분석 (Development of the submerged heat treatment machine for PBSAT(polybutylene succinate adipate-co-terephthalate) monofilament nets and its efficiency)

  • 박성욱;김성훈;임지현;최혜선
    • 수산해양기술연구
    • /
    • 제51권1호
    • /
    • pp.94-101
    • /
    • 2015

  • The heat treatment machine based on immersion was developed to reduce temperature difference during netting process and appraised it performance compared current heat treatment machine using high pressure. It was also reviewed the optimum heat treatment procedures for PBSAT monofilament net in accordance with the immersion time and temperature. The procedure was based on physical measurement such as breaking load, elongation and angle of the mesh for PBSAT monofilament. The water temperature gap of the treatment machine based on immersion was less than $1^{\circ}C$. and the energy consumption was also increased in high temperature condition. It was identified that the optimum temperature was $75^{\circ}C$ and its optimum processing time was between 15 minutes and 20 minutes to get qualified physical properties.

  • https://doi.org/10.3796/KSFT.2015.51.1.094 인용 PDF KSCI

Propionibacterium shermanii에 의한 Vitamin $B_{12}$생성에 영향을 미치는 발효조건에 관한 연구 (Study on the Fermentation Conditions Influencing the Production of Vitamin $B_{12}$ by Propionibacterium shermanii)

  • 김지영;김공환구양모
    • KSBB Journal
    • /
    • 제7권2호
    • /
    • pp.126-131
    • /
    • 1992

  • P. shermanii IFO 1239을 이용 vitamin $B_{12}$를 생산할 때 산소의 영향은 매우 큼 것으로 나타났는데 배양 전반부는 혐기적 조건이, 후반부는 호기적 조건이 vitamin $B_{12}$ 생성증진에 효과적임이 밝혀졌다. 본 연구를 통하여 배양 48시간 동안은 복합배지상에서 혐기적으로 배양하다가 48시간 이후부터는 합성배지로 바꾸고 호기적 조건으로 배양해주는 방법이 vitamin $B_{12}$ 의 생성을 증가시켰다. 이런 배양방법을 이용하여 탄소원과 유기산이 vitamin $B_{12}$ 생성에 미치는 영향을 알아본 결과 glucose, fructose, lactose가 좋은 탄소원이었으며 유기산 중에서는 succinate 와 malate가 각각 34.9%와 18.7%의 vitamin $B_{12}$생성을 촉진시켰다.

  • PDF