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
Cd_(0.5)Zn_(0.5)S film samples are prepared by a spray pyrolysis technique using aqueous solutions of CdC_(l2),ZnC_(l2),SC(NH2)2 and deionized water,which are atomized using compressed air as the carrier gas onto glas...Cd_(0.5)Zn_(0.5)S film samples are prepared by a spray pyrolysis technique using aqueous solutions of CdC_(l2),ZnC_(l2),SC(NH2)2 and deionized water,which are atomized using compressed air as the carrier gas onto glass substrates with different water(H2O)concentrations.H2O is used as the activator.The prepared films are characterized by means of XRD and UV−VIS spectroscopy.Experimental results reveal that the structures and properties of the films are greatly affected by the H2O content.Water in a certain range of concentrations promotes the formation of the Cd_(0.5)Zn_(0.5)S films and improves the properties of the films.展开更多
With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we m...With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we must reckon with the energy balance of the whole process. Densification and processing of microalgae can consume 50% - 70% of the energy that can be extracted from the cells,?therefore the cultivation should use such a little energy as it possible. In closed cultivation systems,?there are three main energy intensive steps: artificial illumination, dissolution of gas compounds and mixing. We have carried out our measurements in our lab-scale screening photobioreactor system for the investigation of the most energy effective program for aeration. We have found the aeration program considerable solution for lower energy consumption in?algae cultivation.展开更多
Electrochemical semihydrogenation of acetylene(C_(2)H_(2))using renewable electricity offers a sustainable route for ethylene(C_(2)H_(4))production.However,the development of this technique has been hindered by many c...Electrochemical semihydrogenation of acetylene(C_(2)H_(2))using renewable electricity offers a sustainable route for ethylene(C_(2)H_(4))production.However,the development of this technique has been hindered by many challenges,such as competitive hydrogen evolution reactions(HERs)and overhydrogenation at high current densities,which will reduce the faradaic efficiency(FE)of C_(2)H_(4) and negatively impact downstream processing.Herein,we develop defectrich copper nanocubes(v-Cu NCs)as efficient electrocatalysts that facilitateC_(2)H_(4) adsorption while suppressing HER and overhydrogenation.The superior semihydrogenation performances are verified by the high C_(2)H_(4) FE of 98.3%at an ultrahigh current density of 0.7 A cm^(−2).Remarkably,in a 25 cm^(2) electrolyzer,v-Cu NCs deliver a record-high single-pass conversion of 97.5%forC_(2)H_(4) and C_(2)H_(4) selectivity of 97.4%at a cathode current of 1.6 A with a flow rate of 10 mL min−1,operating stably for 50 h.In-situ Raman spectroscopy and theoretical calculations reveal that uniformly oriented Cu(100)planes and nitrogen vacancies generate strongC_(2)H_(4) adsorption at copper sites,which facilitates hydrogenation kinetics and increases the energy barrier for overhydrogenation.This work offers valuable insights into the implementation ofC_(2)H_(4)-to-C_(2)H_(4) production and the development of efficient electrocatalysts forC_(2)H_(4) semihydrogenation.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Cd_(0.5)Zn_(0.5)S film samples are prepared by a spray pyrolysis technique using aqueous solutions of CdC_(l2),ZnC_(l2),SC(NH2)2 and deionized water,which are atomized using compressed air as the carrier gas onto glass substrates with different water(H2O)concentrations.H2O is used as the activator.The prepared films are characterized by means of XRD and UV−VIS spectroscopy.Experimental results reveal that the structures and properties of the films are greatly affected by the H2O content.Water in a certain range of concentrations promotes the formation of the Cd_(0.5)Zn_(0.5)S films and improves the properties of the films.
文摘With autotrophic microalgae cultivation,?we can feed back the CO2?content of process streams and we can get lots of valuable organic compounds, among others biofuel components. For the production of energy source,we must reckon with the energy balance of the whole process. Densification and processing of microalgae can consume 50% - 70% of the energy that can be extracted from the cells,?therefore the cultivation should use such a little energy as it possible. In closed cultivation systems,?there are three main energy intensive steps: artificial illumination, dissolution of gas compounds and mixing. We have carried out our measurements in our lab-scale screening photobioreactor system for the investigation of the most energy effective program for aeration. We have found the aeration program considerable solution for lower energy consumption in?algae cultivation.
基金supported by the National Natural Science Foundation of China(grant nos.22322807,22168023,22268029,and 22108243)the Natural Science Foundation of Jiangxi Province(grant no.20224ACB204003)+1 种基金the China Scholarship Council(grant no.202206820025)the Australian Research Council(ARC)through the ARC Discovery project(grant no.DP230101579).
文摘Electrochemical semihydrogenation of acetylene(C_(2)H_(2))using renewable electricity offers a sustainable route for ethylene(C_(2)H_(4))production.However,the development of this technique has been hindered by many challenges,such as competitive hydrogen evolution reactions(HERs)and overhydrogenation at high current densities,which will reduce the faradaic efficiency(FE)of C_(2)H_(4) and negatively impact downstream processing.Herein,we develop defectrich copper nanocubes(v-Cu NCs)as efficient electrocatalysts that facilitateC_(2)H_(4) adsorption while suppressing HER and overhydrogenation.The superior semihydrogenation performances are verified by the high C_(2)H_(4) FE of 98.3%at an ultrahigh current density of 0.7 A cm^(−2).Remarkably,in a 25 cm^(2) electrolyzer,v-Cu NCs deliver a record-high single-pass conversion of 97.5%forC_(2)H_(4) and C_(2)H_(4) selectivity of 97.4%at a cathode current of 1.6 A with a flow rate of 10 mL min−1,operating stably for 50 h.In-situ Raman spectroscopy and theoretical calculations reveal that uniformly oriented Cu(100)planes and nitrogen vacancies generate strongC_(2)H_(4) adsorption at copper sites,which facilitates hydrogenation kinetics and increases the energy barrier for overhydrogenation.This work offers valuable insights into the implementation ofC_(2)H_(4)-to-C_(2)H_(4) production and the development of efficient electrocatalysts forC_(2)H_(4) semihydrogenation.
