• Title/Summary/Keyword: Biological and physical properties

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The Effect of chemical and physical properties of Korean tales on the decomposition of Malathion in dust formulations

  • Kang, Duk-Chae;Lee, Sung-Hwan;Cho, Chai-Moo
    • Applied Biological Chemistry
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    • v.2
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    • pp.45-52
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    • 1961
  • The decomposition of malathion in dust for mulations prepared from four Korean tales as carriers during storage period has been studied. Amberlite CG-120, a cation exchange resin . which has higher cation exchange capacity than tales, was also used as a carrier in hope of finding out the effect of nagative charge upon the decomposition of malathion. Besides the original talc powders obtained directly from the mines, the hydrogen ion saturated forms were also used as carriers for comparisonal study. The saturated ions for the resin were hydrogen, sodium and magnesium. As the physical properties of the tales, colloid content, water adsorption capacity, PH, specific surface, phosphate fixing capacity and exchangeable canons were determined, and these properties were correlated with the amount of the decomposition. Following results were obtained from the experiment. 1. The malathion in the talc in dust was found to decompose around 10-15% ofthe total withina month. About 50% of the decom position that took place after a month was found to occur within a week. 2. The resin which has higher cation exchange capacity than the tales was highly effective in the decomposition of malathion compared with the tales. 3. In every case the saturation of the exchange complexes with hydrogen ion greatly accelerated the decomposition of malathion. 4. The most highly correlated physical properties with the decomposition were colloid content and specific surface of the tales. 5. The water adsorption and phosphate fixing capacities of the tales were found not to correlate with the amount of malathion decomposed. From the experimental results it was concluded that the active negative spots on the colloidal tales or the resin attract the electropositive phosphorus atom in a malathion molecule thereby inducing the decomposition easier. The presence of hydrogen ion nearby might cause a catalytic effect in the decomposition of malathion.

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Complex Dynamical Networks: An Overview

  • Chen, Guanrong
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.94.5-94
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    • 2002
  • The current study of complex dynamical networks is pervading all kinds of sciences today, ranging from physical to biological, even to social sciences. its impact on modern engineering and technology is prominent and will be far-reaching. Typical complex dynamical networks include the World Wide Web, the Internet, various wireless communication networks, meta-bolic networks, biological neural networks, social connection networks, scientific cooperation and citation networks, and so on. Research on fundamental properties and dynamical features of such complex networks have become overwhelm ing. This talk will provide a brief overview of some basic concepts about com plex dynamical netwo...

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Biodegradable Inorganic-Organic Composite Artiticial Bone Substitue -Part2. Collagen purification and its physical and biological properties-

  • Hwal Suh
    • Journal of Biomedical Engineering Research
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    • v.15 no.3
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    • pp.341-346
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    • 1994
  • To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atel- ocollagen was produced. The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength.

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Mechanical Properties of Rice Plants Under the Transverse Loading -Creep and Recovery Behavior- (측방향하중(側方向荷重)에 의한 벼줄기의 역학적특성(力學的特性)에 관한 연구(硏究)(II) -크리이프 및 회복 거동-)

  • Huh, Yun Kun
    • Korean Journal of Agricultural Science
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    • v.23 no.2
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    • pp.233-241
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    • 1996
  • The mechanical properties of biological materials depend on numerous factors. The majority of these relationships are still unknown today, especially with regard to their quantitative characteristics. The reason is that biological materials constitute biomechanical systems of very complex construction, whose behavior cannot be characterized by simple physical constants, as for example can that of engineering materials. The objectives of this investigation were to determine the compression creep and recovery properties of rice stalks at various levels of applied load The compression creep and recovery behavior of the rice stalk could be predicted precisely by rheological model which approached closely to the measured values. But the coefficients of the Burgers recovery model were different from those of the creep model. The Steady state creep behavior occurred at the higher level of force and the logarithmic creep behavior occurred at the lower level of force. The mechanical model being expected the creep behavior in relation with the level of applied load, which was well explained that the rice stalk might be visco-elastic material.

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Evaluation of the Extraction Process in the Recycling of the Biological Waste (폐생물자원 활용에서 추출공정의 특성 평가)

  • Sung, Yong-Joo;Han, Young-Lim;Kim, Kun-Soo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.3 s.116
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    • pp.72-78
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    • 2006
  • The extraction properties of the biological waste originated from the Tobacco industry were evaluated. The biological waste have been recycled and transformed into a valuable material, so called a reconstituted tobacco sheet(Recon) by the papermaking process. In this process, The mechanical extraction process, which divides the mixed raw material slurry into the soluble stock and the insoluble stock, could affect not only the quality of final Recon product but also the productivity of whole Recon making process. This study investigated the effects of the extraction process on the slurry properties in detail. In order to quantify the amounts of the solubles which resided in the insoluble fibers, the washing treatment of the stock before and after squeezing process was applied. The amounts of the residual solubles showed little changes according to each stage of the extraction process. The fractionation of the slurry showed the difference in the amount of soluble in the stock depending on the size of the biological waste. After the extraction process, the bigger size fiber portion contained about 19%(by weight) in soluble after pressing but the smaller size fiber portion 9% in soluble. The fractionation ratio of the stocks also was changed by the screw press process, which could demonstrate the physical effects of the mechanical extraction.

Dissolution Profiles of Solid Dispersions Containing Poorly Water-Soluble Drugs and Solubilizing Compositions (가용화 조성물과 난용성 약물군을 함유하는 고체분산체의 용출양상)

  • Kim, Tae-Wan;Choi, Choon-Young;Cao, Qing-Ri;Kwon, Kyoung-Ae;Lee, Beom-Jin
    • Journal of Pharmaceutical Investigation
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    • v.32 no.3
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    • pp.191-197
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    • 2002
  • Polymer based physical mixtures or solid dispersions containing solubilizing compositions[OA, tween80 and SLS] were prepared using a spray-dryer. Lovastatin(LOS), simvastatin(SIMS), aceclofenac(AFC) and cisapride(CSP) were selected as poorly water-soluble drugs. Dextrin, poly(vinylalcohol) (PVA), poly(vinylpyrrolidone)(PVP) and polyethylene glycol(PEG) were chosen as solubilizing carriers for solid dispersions. The solid dispersions containing solubilizing compositions without drug were prepared without using organic solvents or tedious changes of formulation compositions. This system could be used to quickly screen the dissolution profiles of poorly water-soluble drugs by simply mixing with drugs thereafter. In case of solid dispersion containing drug, organic solvent systems could be used to solubilize model drugs. The dissolution rates of the drugs were higher when mixed with drug and solid dispersions containing solubilizing compositions. However, solid dispersions of LOS, AFC, and CSP simultaneously containing drug and solubilizing compositions in organic solvent systems were more useful than physical mixtures of drug and solid dispersions without drug except SIMS. Based on solubilizing capability of polymer based physical mixtures in gelatin hard capsules, optimal solid dispersion system of poorly water-soluble drugs could be formulated. However, it should be noted that dissolution rate of poorly water-soluble drugs were highly dependent on drug properties, solubilizing compositions and polymeric carriers.

The effect of sewage sludge compost amended soils on the growth of Orchardgrass seedlings (하수오니 첨가토양이 Orchardgrass 유식물체의 생육에 미치는 영향)

  • Lee, Ju Sam
    • Journal of the Korea Organic Resources Recycling Association
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    • v.2 no.2
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    • pp.77-88
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    • 1994
  • This experiment was carried out to investigate the effect of sewage sludge compost amended soils on the growth and accumulation patterns of heavy metals in plant parts of Orchardgrass seedlings, changes in physical properties and chemical composition, and heavy metal residue in soils. Mixture ratios of sewage sludge compost and soil(loam) were 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100(control), respectively. The results obtained were as follows; 1. The physical properties and chemical compostion of soils were improved by increase in mixture ratios of sewage sludge compost. 2. The biological yield of Orchardgrass seedlings was increased with mixture ratios of sewage sludge compost. 3. The dry weight of shoot(SH) was increased with both of yield components(NT and WT) and biological yield of Orchardgrass seedlings. 4. The total nitrogen concentrations(TN) of plants was increased with quadratically up to the biological yield of 100% mixture ratio of sewage sludge compost. 5. Lead(Pb) concentration of soil in over the 60% mixture ratios of sewage sludge compost were in excess of limiting level(50ppm) of organic fertilizers.

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Versatile Strategies for Fabricating Polymer Nanomaterials with Controlled Size and Morphology

  • Yoon, Hyeon-Seok;Choi, Moon-Jung;Lee, Kyung-Jin;Jang, Jyong-Sik
    • Macromolecular Research
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    • v.16 no.2
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    • pp.85-102
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    • 2008
  • The development of reliable synthetic routes to polymer nanomaterials with well-defined size and morphology is a critical research topic in contemporary materials science. The ability to generate nanometer-sized polymer materials can offer unprecedented, interesting insights into the physical and chemical properties of the corresponding materials. In addition, control over shape and geometry of polymer nanoparticles affords versatile polymer nanostructures, encompassing nanospheres, core-shell nanoparticles, hollow nanoparticles, nanorods/fibers, nanotubes, and nanoporous materials. This review summarizes a diverse range of synthetic methods (broadly, hard template synthesis, soft template synthesis, and template-free synthesis) for fabricating polymer nanomaterials. The basic concepts and significant issues with respect to the synthetic strategies and tools are briefly introduced, and the examples of some of the outstanding research are highlighted. Our aim is to present a comprehensive review of research activities that concentrate on fabrication of various kinds of polymer nanoparticles.

Polysiloxanes Containing Alkyl Side Groups: Synthesis and Mesomorphic Behavior

  • Kim, Byoung-Gak;Moon, Jin-Kyung;Sohn, Eun-Ho;Lee, Jong-Chan;Yeo, Jong-Kee
    • Macromolecular Research
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    • v.16 no.1
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    • pp.36-44
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    • 2008
  • A series of polysiloxanes containing alkylsulfonyl side groups were synthesized using a polymer analogous reaction beginning from poly(methylhydrosiloxane) and the corresponding olefins. These polymers showed a mesomorphic behavior with smectic liquid crystalline phases. The chemical and physical properties of these polymers were examined using nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry, optical polarizing microscopy, and X-ray diffraction.

Effect of Rice Bran and Wood Charcoal on Soil Properties and Yield of Continuous Cropping of Red Pepper

  • Won, J.G.;Jang, K.S.;Hwang, J.E.;Kwon, O.H.;Jeon, S.G.;Park, S.G.;Park, K.C.;Suh, Y.J.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.218-221
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    • 2011
  • To improve the soil properties of physical and microbial community rice bran and wood charcoal were applied in the continuously cultivated plastic film house soil. Soil physical properties were improved by application of rice bran and charcoal compared to chemical fertilizer application (control) by 8~14% in bulk density and 5~9% in soil porosity. Changes in the biological ratio indexes of fatty acids in the soils were detected depending on the inputted materials. Especially in application of rice bran including mixture with charcoal, much more fungi and less bacteria were detected and the ratio of fungi to bacteria was increased, suggesting the more organic carbon metabolically active in these treatments. The high ratio of aerobe to anaerobe suggested the better aerobic conditions were in the soil inputted wood charcoal. From these results, it is important and possible to select some materials for the organic pepper cultivation, which may improve the poor condition soil.