poly(ethyleneglycol)/poly(butylenesterephthalate)(PEG/PBT)已经在最近作为生物可降解材料应用于组织工程之中[1,2,3].现在,在PEG/PBT的基础上合成了两种新型材料,它们是:poly(butylen esterephthalate co 1,4 cyclohexenedimethylen...poly(ethyleneglycol)/poly(butylenesterephthalate)(PEG/PBT)已经在最近作为生物可降解材料应用于组织工程之中[1,2,3].现在,在PEG/PBT的基础上合成了两种新型材料,它们是:poly(butylen esterephthalate co 1,4 cyclohexenedimethylenetere phthalate b ethyleneglycolterephthaloyl)(PTCG),和poly(butylenesterephthalate) co poly(butylenessuccinate) b poly(ethyleneglycol)(PTSG).它们具有两种硬片段,这使它们能够比PEG/PBT更好地调整材料的组分以使得它们能够具有更合适的可降解速度和更好的力学性质.还可以使它们能够减少硬片段的容量和长度,同时还不牺牲材料的力学性质,使材料对于人体更为安全.所以,如果这两种材料的生物相容性一律良好,它们将会比PEG/PBT在组织工程中有更好的应用前景.展开更多
Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether （ETBE）, from etha-nol and tert-butyl alcohol （TBA） has been studied in catalytic distillation column （CDC） using ion exchange...Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether （ETBE）, from etha-nol and tert-butyl alcohol （TBA） has been studied in catalytic distillation column （CDC） using ion exchange resin catalyst CT-145H. A packed CDC of 1.2 m height and 50 mm diameter with indigenously developed reactive sec-tion packing was used to generate experimental data. Effect of different key variables on product purity in distillate, was investigated to find the optimum operating conditions for ETBE synthesis. The optimum conditions for 0.2 kg·s-1 of ethanol feed were found：reboiler duty of 375 W, molar feed ratio of 1︰1.3 of reactants, and reflux ratio of 7. Concentration profiles for each component along each column section at optimum conditions were also drawn. Neither output nor input multiplicity was observed at experimental conditions.展开更多
Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified dip...Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerize and modify once more. The system was applied in composites. Their properties were investigated and found that they met the requirements as a heat-resisting adhesive.展开更多
Castor oil is used to synthesize phenolic resin modified polyol. Castor oil, phenolic resin were taken in the molar ratio 0.07：0.027 and diethylene glycol （DEG） was also taken in varying hydroxyl numbers to achieve...Castor oil is used to synthesize phenolic resin modified polyol. Castor oil, phenolic resin were taken in the molar ratio 0.07：0.027 and diethylene glycol （DEG） was also taken in varying hydroxyl numbers to achieve chemical modification in the backbone of synthesized polyol. Physico-chemical properties like acid value, OH value and moisture content of the modified polyol were measured. The prepared phenolic resin blended polyol were reacted with 4, 4-methylene diisocyanate and 2, 4-toluene diisocyanate to formulate the two component polyurethane （PU） coatings. Prepared coating is used to study properties such as gel time, surface dry, tack free and hard surface drying times. It was found that phenolic resin and diethyleneglycol used in synthesizing castor oil based modified polyols show the significant changes in physico-chemical properties of synthesized polyols. The variation in physico-chemical properties of synthesized polyol provide the information for desirable curing of polyurethane systems.展开更多
The present study was conducted to investigate antifungal activity ofLawsonia inermis （Henna plant）. Leaf samples of the plants were collected from Eastern Nile of Khartoum state, Sudan. Ethanol and petroleum ether ...The present study was conducted to investigate antifungal activity ofLawsonia inermis （Henna plant）. Leaf samples of the plants were collected from Eastern Nile of Khartoum state, Sudan. Ethanol and petroleum ether extracts in various concentrations were obtained by maceration （cold method）. The extracts were bioassay in vitro to know their bioactivity to inhibit the growth of tested fungi. The cup plate agar diffusion method was adopted to assess the antifungal activity of the extracts against tested yeasts while agar incorporated method was used for other molds. Both extracts revealed anti fungal activity against all yeast strains except Pichiafabianii which was found resistant to both ethanol and ether extracts. The results displayed antifungal activity against tested fungi. Minimum mould concentration （MMC） of the extracts was determined. The obtained results revealed antifungal activity of henna leaves extracts which support the traditional use of the Henna in therapy of fungal infections. The possibility of therapeutic use of Sudanese henna as antifungal agents is recommended.展开更多
基金the National Hi-Tech"863"Plan Fund(2001AA216077)"Tissue Engineering"special item from Beijing Science and Technology Committee(H020920040330).
文摘poly(ethyleneglycol)/poly(butylenesterephthalate)(PEG/PBT)已经在最近作为生物可降解材料应用于组织工程之中[1,2,3].现在,在PEG/PBT的基础上合成了两种新型材料,它们是:poly(butylen esterephthalate co 1,4 cyclohexenedimethylenetere phthalate b ethyleneglycolterephthaloyl)(PTCG),和poly(butylenesterephthalate) co poly(butylenessuccinate) b poly(ethyleneglycol)(PTSG).它们具有两种硬片段,这使它们能够比PEG/PBT更好地调整材料的组分以使得它们能够具有更合适的可降解速度和更好的力学性质.还可以使它们能够减少硬片段的容量和长度,同时还不牺牲材料的力学性质,使材料对于人体更为安全.所以,如果这两种材料的生物相容性一律良好,它们将会比PEG/PBT在组织工程中有更好的应用前景.
基金Part of this paper was included in the proceedings of World Congress on Engineering and Computer Science,San Francisco,USA,22-24 October,2008,pp.79-84(ISBN 978-988-98671-0-2)The first author is grateful to Higher Education Commission of Pakistan for funding this research under indigenous scheme
文摘Liquid phase synthesis of one of the important fuel oxygenate, ethyl tert-butyl ether （ETBE）, from etha-nol and tert-butyl alcohol （TBA） has been studied in catalytic distillation column （CDC） using ion exchange resin catalyst CT-145H. A packed CDC of 1.2 m height and 50 mm diameter with indigenously developed reactive sec-tion packing was used to generate experimental data. Effect of different key variables on product purity in distillate, was investigated to find the optimum operating conditions for ETBE synthesis. The optimum conditions for 0.2 kg·s-1 of ethanol feed were found：reboiler duty of 375 W, molar feed ratio of 1︰1.3 of reactants, and reflux ratio of 7. Concentration profiles for each component along each column section at optimum conditions were also drawn. Neither output nor input multiplicity was observed at experimental conditions.
文摘Modified diphenyl oxide resin was synthesized by co-polymerization of unsaturated acid and diphenyl oxide derivants. And then modified bismaleimide resin and expoxide linear phenolic resin were added into modified diphenyl oxide resin to co-polymerize and modify once more. The system was applied in composites. Their properties were investigated and found that they met the requirements as a heat-resisting adhesive.
文摘Castor oil is used to synthesize phenolic resin modified polyol. Castor oil, phenolic resin were taken in the molar ratio 0.07：0.027 and diethylene glycol （DEG） was also taken in varying hydroxyl numbers to achieve chemical modification in the backbone of synthesized polyol. Physico-chemical properties like acid value, OH value and moisture content of the modified polyol were measured. The prepared phenolic resin blended polyol were reacted with 4, 4-methylene diisocyanate and 2, 4-toluene diisocyanate to formulate the two component polyurethane （PU） coatings. Prepared coating is used to study properties such as gel time, surface dry, tack free and hard surface drying times. It was found that phenolic resin and diethyleneglycol used in synthesizing castor oil based modified polyols show the significant changes in physico-chemical properties of synthesized polyols. The variation in physico-chemical properties of synthesized polyol provide the information for desirable curing of polyurethane systems.
文摘The present study was conducted to investigate antifungal activity ofLawsonia inermis （Henna plant）. Leaf samples of the plants were collected from Eastern Nile of Khartoum state, Sudan. Ethanol and petroleum ether extracts in various concentrations were obtained by maceration （cold method）. The extracts were bioassay in vitro to know their bioactivity to inhibit the growth of tested fungi. The cup plate agar diffusion method was adopted to assess the antifungal activity of the extracts against tested yeasts while agar incorporated method was used for other molds. Both extracts revealed anti fungal activity against all yeast strains except Pichiafabianii which was found resistant to both ethanol and ether extracts. The results displayed antifungal activity against tested fungi. Minimum mould concentration （MMC） of the extracts was determined. The obtained results revealed antifungal activity of henna leaves extracts which support the traditional use of the Henna in therapy of fungal infections. The possibility of therapeutic use of Sudanese henna as antifungal agents is recommended.
