• 제목/요약/키워드: Chemical pulp

검색결과 479건 처리시간 0.033초

Qualitative Evaluation of Ligninolytic Enzymes in Xylariaceous Fungi

  • Lee, Yang-Soo
    • Journal of Microbiology and Biotechnology
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    • 제10권4호
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    • pp.462-469
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    • 2000
  • Sixty-one strains representing the main genera of wood-decaying xylariaceous fungi (mainly in Daldinia, Hypoxylon, Kretzschmaria, Rosellinia, Penzigia, and Xylaria) were tested for their ability to produce ligninolytic enzymes. The phenol oxidase activity and fungal growth of the xylariaceous fungi on gallic aicid and tannic acid media showed a variation in their ability to degrade lignocellulose. A number of species showed equal 개 betterligninolytic enzyme activities than Coriolus versicolor, a known basidiomycete wood-degrader. A large variation of the enzyme activity was observed by individual strains as well as a substantial variation between the isolates of the same species. The most frequent ligninolytic enzymes were peroxidase and general oxidase. With 19% of the strains tested, peroxidase showed the strongest ligninolytic enzyme activity, while tyrosinase activity was detected only in 7% of the strains. All strains of Kretzschmaria and Rosellinia tested was positive for laccase. Xylariaceous fungi were able to degrade the macromolecule, lignin, using each specific ligninolytic enzyme in the specfic lignin degradation pathway.

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Antioxidant Activity of Flavonoids and Their Glucosides from Sonchus oleraceus L.

  • Yin, Jie;Si, Chuan-Ling;Wang, Myeong-Hyeon
    • Journal of Applied Biological Chemistry
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    • 제51권2호
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    • pp.57-60
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    • 2008
  • Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

A study of Energy Oriented Urban Development Model for Industrial Complex plan

  • Kim, Sang-hyun
    • 기술혁신학회지
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    • 제8권1호
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    • pp.209-219
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    • 2005
  • o Korea consumed total 198.5 million TOE and the portion of crude oil n was 100.4 million TOE in 2002 which marked the 10th largest energy consuming country and ranks the $4^{th}$ crude oil consumer in the world. o Industries consumed 51.5% of the total energy and 93% of industrial energy was used at the manufacturing industries such as steel, textile, chemical, food and beverage, pulp and paper, and timber industries, which lead to energy intensive industries numbered 110,000. o Also Korea ranks the $10^{th}$ greenhouse gas emission countries of the world (134.9 million TC) which may cause Korean industries to suffer severely during the implementation of United Nations Framework Convention on Climate Change (UNFCCC). o Therefore, the target of the study is to develop a model for the analysis and design of industrial complex by integration of the energy usage and environmental problems. o The research work contents are as followings: -Analysis of Korea energy consumption -Concept of the integration of energy and environment problems - Basic concept of industrial complex planning - Case study (1) - Recommendation and conclusion

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Antioxidant Effect of Juglans mandshurica Bark Gallotannins

  • Si, Chuan-Ling;Bae, Young-Soo
    • Journal of Forest and Environmental Science
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    • 제23권1호
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    • pp.1-4
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    • 2007
  • The bark of Juglans mandshurica Maxim. was collected, extracted with acetone-$H_2O$ (7:3, v/v), fractioned with n-hexane, $CH_2Cl_2$ and EtOAc, then each fraction was freeze-dried to give some powders. A portion of the EtOAc (28.4 g) fraction was chromatographed on a Sephadex LH-20 column eluting with a series of MeOH-$H_2O$ and EtOH-hexane mixture. Four gallotannins, gallic acid (1), ellagic acid (2), 1,2,4,6-tetra-O-galloyl-${\beta}$-D-glucose (3) and 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-glucose (4), have been isolated from the EtOAc fraction Their structures were elucidated on the basis of chemical evidence and spectrometric analysis such as NMR and MS. The antioxidant activities on each fraction and the isolated gallotannins were evaluated by DPPH radical scavenging test.

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Antioxidant Constituents from Leonurus japonicus

  • Qu, Guan-Zheng;Si, Chuan-Ling;Wang, Myeong-Hyeon
    • Natural Product Sciences
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    • 제12권4호
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    • pp.197-200
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    • 2006
  • Two phenolic acids, gallic acid (1) and syringic acid (2), and five flavonoids, apigenin (3), luteolin (4), kaempferol (5), quercetin (6), and myricetin (7), were isolated from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectral analysis. The antioxidant activities of the crude extracts, partitioned fractions and isolated compounds were evaluated by DDPH free radical-scavenging assay. Results suggested that the EtOAc partitioned fraction and compounds 1, 4, 5, 6, and 7 showed significantly high antioxidant potential compared with $\alpha-tocopherol$ and BHT, which were used as controls.

Dispersion Polymerization of Acrylamide in Methanol/Water Media

  • Lee, Ki-Chang;Lee, Seung-Eun;Song, Bong-Keun
    • Macromolecular Research
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    • 제10권3호
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    • pp.140-144
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    • 2002
  • Dispersion polymerization of acrylamide was carried out in the media of methyl alcohol/$H_2O$ mixtures using hydroxypropyl cellulose and ammonium persulfate as steric stabilizer and initiator, respectively. The effects of concentrations of initiator and steric stabilizer, amount of monomer, polymerization temperature, methyl alcohol/$H_2O$ ratio, and purification of monomer and nitrogen purge on the particle size of the latices and molecular weight of the polymers were investigated. The average particle diameter increased with increasing concentration of initiator, water content in methyl alcohol/$H_2O$ media, and polymerization temperature, but decreased with monomer and stabilizer concentrations. The viscosity average molecular weight increased with increasing concentrations of monomer, steric stabilizer, and water content in dispersion media, but decreased with initiator concentration and polymerization temperature. The PAM polymers prepared with the purified monomer and the nitrogen purging before the reaction showed the highest molecular weight.

Cerebrosides from Longan Arillus

  • Ryu, Ji-Young;Kim, Ju-Sun;Kang, Sam-Sik
    • Archives of Pharmacal Research
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    • 제26권2호
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    • pp.138-142
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    • 2003
  • From the pulp of Euphoria longana (Longan Arillus), three cerebroside molecular species have been isolated. Six known cerebrosides, soyacerebrosides I and II, 1-Ο-$\beta$-D-glucopyranosyl-(2S,3R,4E,8E)-2-(2 -lignoceroylamino)-4,8-octadecadiene-1,3-diol (long an cerebroside I) and its 8Z isomer (Iongan cerebroside II), momor-cerebroside I, and phytolacca cerebroside, were identified as major components of these cerebroside molecular species. All the cerebrosides were shown to be a mixture of geometrical isomers (8E and 8Z) of sphingosine-type or phytosphingosine-type glucocerebrosides possessing 2-hydroxy fatty acids. The structures of these cerebrosides have been determined on the basis of chemical and spectroscopic evidence.

An Overview of NRC Projects in Wastewater Treatment by Membrane Processes

  • Kumar, Ashwani
    • 한국막학회:학술대회논문집
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    • 한국막학회 1997년도 제5회 하계 Workshop (97 한,카 국제공동 Workshop, 고도 수처리를 위한 막분리 공정)
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    • pp.55-66
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    • 1997
  • A brief introduction to NRC's research activities will be given with special emphasis on membrane processes. NIRC's membrane research group has been involved in many membrane research projects with industrial clients in various sectors of the industry. These projects generally were focused on using membranes for treating industrial wastewater streams for recycling process water, recovering of valuable components and meeting the environmental regulations. The group looked in to various aspects of process development dealing with membrane performance evaluation, optimization of operational parameters, determination of fouling propensities of membranes and simple cost analyses in some cases. Case studies dealing with process development for effluent treatment for the pulp & paper, mining & mineral processing and poultry processing industries will be discussed briefly.

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Application of Low Voltage High Resistance Grounding in Nuclear Power Plants

  • Chang, Choong-Koo;Hassan, Mostafa Ahmed Fouad
    • Nuclear Engineering and Technology
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    • 제48권1호
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    • pp.211-217
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    • 2016
  • Most nuclear power plants now utilize solid grounded low voltage systems. For safety and reliability reasons, the low voltage (LV) high resistance grounding (HRG) system is also increasingly used in the pulp and paper, petroleum and chemical, and semiconductor industries. Fault detection is easiest and fastest with a solidly grounded system. However, a solidly grounded system has many limitations such as severe fault damage, poor reliability on essential circuits, and electrical noise caused by the high magnitude of ground fault currents. This paper will briefly address the strengths and weaknesses of LV grounding systems. An example of a low voltage HRG system in the LV system of a nuclear power plant will be presented. The HRG system is highly recommended for LV systems of nuclear power plants if sufficient considerations are provided to prevent nuisance tripping of ground fault relays and to avoid the deterioration of system reliability.

Bio-Soda Pulping of Rice Straw with Pleurotus cornucopiae under Atmospheric Pressure

  • Ju, Yong-Chan;Kang, Jin-Ha
    • 펄프종이기술
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    • 제35권5호
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    • pp.62-71
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    • 2003
  • This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose + N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose + N were added, the physical properties showed superior results during each incubation period.