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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Physical Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Simulation,Graphene,defect,Shear’s modulus
- چکیده:
- چکیده انگلیسی: Graphene sheet including single vacancy, double vacancy and Stone-Wales with armchair and zigzag structure was simulated using molecular dynamics simulation. The effect of defects on shear’s modulus, shear strength and fracture strain was investigated. Results showed that these shear properties reduce when the degrees of all kinds of defects increase. The dangling bond in SV and DV defected graphene leads to decrease its mechanical properties especially shear strength and fracture strain where the role of weak interatomic bonds are important. The vacancies in DV defected graphene are also next to each other and slide over each other under shear deformation results to less shear strength than that of SV defected graphene. Results can be useful in tuning the mechanical properties of graphene-based materials that is a key-role parameter in designing and fabrication of nanomechanical systems. However, the maximum and minimum reduction occurs for single vacancy and Stone-Wales defects, respectively. It was also found that distinction between shear properties of zigzag and armchair structures is preserved in defected graphene.
- انتشار مقاله: 18-03-1394
- نویسندگان: Salimeh Kimiagar,Ali Rajabpour,Fatemeh Tavazoee
- مشاهده
- جایگاه : پژوهشی
- مجله: Avicenna Journal of Phytomedicine
- نوع مقاله: Journal Article
- کلمات کلیدی: Essential oils,Pelargonium roseum,Artemisia sieberi,Greenhouse Cucumber,Organic Product,Potato Whitefly,Sweet
- چکیده:
- چکیده انگلیسی: Objective: Sweet potato whitefly, Bemisia tabaci Gen. (B. tabaci), is one of the most important pests of various greenhouse crops in Iran. Nowadays, chemical insecticides are broadly used for control of the pests that causes risk to consumer's health. For the first time, contact toxicity of Pelargonium roseum Andrews and Artemisia sieberi Besser essential oils on B. tabaci and its possible application against the whitefly was evaluated in 2012.
Materials and Methods: Essential oil with concentrations of 2500, 1250, 125, and 12 ppm were used. Infested leaves of greenhouse cucumber were treated by mentioned concentrations. After 24 hours, mortality of B. tabaci was recorded and compared after correcting by Abbot's formula.
Results: Results showed that all concentrations of the essential oil could significantly reduce population of B. tabaci compared with the control treatment. Phytotoxicity of the treated leaves were recorded after 24, 48, and 72 hours and compared with the control. Concentrations of 2500, 1250, and 125 ppm caused severe phytotoxicity on greenhouse cucumber leaves and therefore are not suitable for greenhouse application. Phytotoxicity of 12 ppm was relatively low.
Conclusions: This data implicated suitable protective effects of the essential oils to the pest infestation. Therefore, essential oils distillated from Geranium and Artemisia could be applied to control B. tabaci in greenhouse cucumber at V/V 12 ppm.- انتشار مقاله: 11-09-1391
- نویسندگان: Fatemeh Yarahmadi,Ali Rajabpour,Nooshin Zandi Sohani,Leila Ramezani
- مشاهده