Objective:To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana(E.chapmaniana)and test the antimicrobial of the nanoparticles against different pathogenic bacteria,yeast and its toxicity agai...Objective:To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana(E.chapmaniana)and test the antimicrobial of the nanoparticles against different pathogenic bacteria,yeast and its toxicity against human acute promyelocytic leukemia(HL-60)cell line.Methods:Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO_3 and exposed to sun light for 1 h.A change from yellowish to reddish brown color was observed.Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed.Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,a yellow tetrazole was obtained on the human leukemia cell line(HL-60).Results:UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm.X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50°and 44.76°.The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.Conclusions:It has been demonstrated that the extract of E.chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution.Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.展开更多
Plasma processes are among the emerging technologies for volatile organic compounds (VOCs) abatement[1]. Both thermal plasmas and non-equilibrium plasmas (cold plasmas) are being developed for VOCs cleanup[2,3]. Parti...Plasma processes are among the emerging technologies for volatile organic compounds (VOCs) abatement[1]. Both thermal plasmas and non-equilibrium plasmas (cold plasmas) are being developed for VOCs cleanup[2,3]. Particularly, pulsed corona discharges offer several advantages over conventional VOCs abatement techniques[4-7]. To optimize the existing technology and to develop it further, there is need to understand the mechanisms involved in plasma chemical reactions. Furthermore, it is strongly desirable to be able to predict the behavior of new VOCs in non-equilibrium plasma environment from the data known for a few representative compounds. Pulsed corona discharge technique is introduced here with citation of relevant literature. Fundamental principles, useful for predicting the VOCs' decomposition behavior, have been worked out from the published literature. Latest developments in the area, targeted to minimize the energy losses, improve the VOCs destruction efficiency and reduce the generation of unwanted organic and inorganic by-products, are presented.展开更多
The extraction of valuables from waste has gained momentum.Thermal infuence alters both the organic and inorganic components of coal.Insufficient knowledge on the association of rare earth elements(REEs)with the paren...The extraction of valuables from waste has gained momentum.Thermal infuence alters both the organic and inorganic components of coal.Insufficient knowledge on the association of rare earth elements(REEs)with the parent matrix of thermally altered high-ash coals(63%ash)limits the potential for such coals being utilized for isolation of valuables.In this study,we analyzed the distribution and occurrence modes of REEs within a magmatically altered high-ash coal via nine-step sequential extraction,combining Tessier and BCR methods.The total concentration of REEs in the coal sample,on whole coal basis,was found to be 820 ppm,which is significantly higher than the world average.Major mineral oxides were deduced to be those of Si,Fe,Al,Ca,Mg,and Ti.Sequential extraction confirmed that about 66%of HREE and 25%of LREE were included in the residual fraction.LREEs were concluded to be primarily in ionic form,whereas HREEs were speculated to be associated with the TiO_(2) phase.XRD analyses showed that thermal alteration affected the dolomite phase specifically,which selectively got removed where carbonate-bound elements were assessed.Petrographic analysis supported the magmatic influence and demonstrated the presence of mosaic structures and pores containing unfused vitrinite,with a reflectance value of 3.6.To summarize,the present study pertaining to delineation of association of valuables in high-ash heat-altered coals from an Eastern coalfeld in India can potentially open up new avenues for utilizing such coals,which are otherwiseconsidered waste.展开更多
Exploration of secondary resources for isolation of valuable constituents,such as rare earth elements(REEs)and trace elements(TEs),is of importance owing to the need to identify new domestic sources and reduce relianc...Exploration of secondary resources for isolation of valuable constituents,such as rare earth elements(REEs)and trace elements(TEs),is of importance owing to the need to identify new domestic sources and reduce reliance on imports.The present study systematically discusses the distribution of REEs and TEs in core samples from the coal block of Bhalukasba Surni{(B1(125 m)-B9(409 m)}located in Rajmahal coalfield,Jharkhand,India,which has not been investigated previously for its geochemistry.The studied coal samples were found to be enriched in TEs whose abundances were in the order of Mn>Mo>Zr>Ni>Cr>V>Cu>Zn>Pb,and REEs(La,Ce,Pr,Nd,Sm,Eu,Gd,Dy,Er,Tm,Yb,Lu)along with Sc and Y.The average concentration of REEs with yttrium(ΣREY)on an ash basis was 528 ppm,which is significantly higher than the world average for coal ash(435 ppm).Of the samples investigated,B3(182-184 m)and B8(396-399 m)demonstrated relatively higher concentrations of potentially economic elements,with B3 containing a higher proportion of middle to heavy REEs Gd,Dy,Ho and Er,and B8 showing relative enrichment in Nd and Y.On dry whole coal basis,B6(275-278 m)showed a considerably higher concentration of Ge(55 ppm)than other samples,whereas the concentration of Zr varied in the range of 90-160 ppm in the whole coal block.X-ray diffraction studies revealed the presence of quartz,keatite,hematite,zircon,anatase and orthoclase in the coal ash samples prepared at 815℃.REEs exhibited prominent positive correlation with Al_(2)O_(3)(0.4<r>0.9)which is supportive of their residence in primary clay minerals such as kaolinite and illite-smectite.Additionally,a positive correlation of REEs with P_(2)O_(5)(0.4<r>0.9)suggests their association with phosphate minerals(such as monazite,xenotime,apatite).Positive correlation with TiO_(2)(r>0.7)corroborates the possible association of REEs with anatase.The morphology of the coal ash samples viewed in SEM showed the presence of Al_(2)O_(3)and SiO_(2)enriched irregular-sponge particles likely derived from partly-fused clay minerals,which accounted for the lower extent of REE encapsulation.The Bhalukasba Surni coal block is potentially of economic importance due to its enrichment in Ge,Zr,and the REEs.展开更多
基金Supported by University of Technology.Baghdad.Iraq and Universiti Kebangsaan Malaysia(Grant No.DIP-2012-02)
文摘Objective:To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana(E.chapmaniana)and test the antimicrobial of the nanoparticles against different pathogenic bacteria,yeast and its toxicity against human acute promyelocytic leukemia(HL-60)cell line.Methods:Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO_3 and exposed to sun light for 1 h.A change from yellowish to reddish brown color was observed.Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed.Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,a yellow tetrazole was obtained on the human leukemia cell line(HL-60).Results:UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm.X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50°and 44.76°.The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.Conclusions:It has been demonstrated that the extract of E.chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution.Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.
文摘Plasma processes are among the emerging technologies for volatile organic compounds (VOCs) abatement[1]. Both thermal plasmas and non-equilibrium plasmas (cold plasmas) are being developed for VOCs cleanup[2,3]. Particularly, pulsed corona discharges offer several advantages over conventional VOCs abatement techniques[4-7]. To optimize the existing technology and to develop it further, there is need to understand the mechanisms involved in plasma chemical reactions. Furthermore, it is strongly desirable to be able to predict the behavior of new VOCs in non-equilibrium plasma environment from the data known for a few representative compounds. Pulsed corona discharge technique is introduced here with citation of relevant literature. Fundamental principles, useful for predicting the VOCs' decomposition behavior, have been worked out from the published literature. Latest developments in the area, targeted to minimize the energy losses, improve the VOCs destruction efficiency and reduce the generation of unwanted organic and inorganic by-products, are presented.
文摘The extraction of valuables from waste has gained momentum.Thermal infuence alters both the organic and inorganic components of coal.Insufficient knowledge on the association of rare earth elements(REEs)with the parent matrix of thermally altered high-ash coals(63%ash)limits the potential for such coals being utilized for isolation of valuables.In this study,we analyzed the distribution and occurrence modes of REEs within a magmatically altered high-ash coal via nine-step sequential extraction,combining Tessier and BCR methods.The total concentration of REEs in the coal sample,on whole coal basis,was found to be 820 ppm,which is significantly higher than the world average.Major mineral oxides were deduced to be those of Si,Fe,Al,Ca,Mg,and Ti.Sequential extraction confirmed that about 66%of HREE and 25%of LREE were included in the residual fraction.LREEs were concluded to be primarily in ionic form,whereas HREEs were speculated to be associated with the TiO_(2) phase.XRD analyses showed that thermal alteration affected the dolomite phase specifically,which selectively got removed where carbonate-bound elements were assessed.Petrographic analysis supported the magmatic influence and demonstrated the presence of mosaic structures and pores containing unfused vitrinite,with a reflectance value of 3.6.To summarize,the present study pertaining to delineation of association of valuables in high-ash heat-altered coals from an Eastern coalfeld in India can potentially open up new avenues for utilizing such coals,which are otherwiseconsidered waste.
文摘Exploration of secondary resources for isolation of valuable constituents,such as rare earth elements(REEs)and trace elements(TEs),is of importance owing to the need to identify new domestic sources and reduce reliance on imports.The present study systematically discusses the distribution of REEs and TEs in core samples from the coal block of Bhalukasba Surni{(B1(125 m)-B9(409 m)}located in Rajmahal coalfield,Jharkhand,India,which has not been investigated previously for its geochemistry.The studied coal samples were found to be enriched in TEs whose abundances were in the order of Mn>Mo>Zr>Ni>Cr>V>Cu>Zn>Pb,and REEs(La,Ce,Pr,Nd,Sm,Eu,Gd,Dy,Er,Tm,Yb,Lu)along with Sc and Y.The average concentration of REEs with yttrium(ΣREY)on an ash basis was 528 ppm,which is significantly higher than the world average for coal ash(435 ppm).Of the samples investigated,B3(182-184 m)and B8(396-399 m)demonstrated relatively higher concentrations of potentially economic elements,with B3 containing a higher proportion of middle to heavy REEs Gd,Dy,Ho and Er,and B8 showing relative enrichment in Nd and Y.On dry whole coal basis,B6(275-278 m)showed a considerably higher concentration of Ge(55 ppm)than other samples,whereas the concentration of Zr varied in the range of 90-160 ppm in the whole coal block.X-ray diffraction studies revealed the presence of quartz,keatite,hematite,zircon,anatase and orthoclase in the coal ash samples prepared at 815℃.REEs exhibited prominent positive correlation with Al_(2)O_(3)(0.4<r>0.9)which is supportive of their residence in primary clay minerals such as kaolinite and illite-smectite.Additionally,a positive correlation of REEs with P_(2)O_(5)(0.4<r>0.9)suggests their association with phosphate minerals(such as monazite,xenotime,apatite).Positive correlation with TiO_(2)(r>0.7)corroborates the possible association of REEs with anatase.The morphology of the coal ash samples viewed in SEM showed the presence of Al_(2)O_(3)and SiO_(2)enriched irregular-sponge particles likely derived from partly-fused clay minerals,which accounted for the lower extent of REE encapsulation.The Bhalukasba Surni coal block is potentially of economic importance due to its enrichment in Ge,Zr,and the REEs.
