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Various Approaches to Transfer Macromolecules into Plants Using Nanoparticles
Published in Devarajan Thangadurai, Saher Islam, Jeyabalan Sangeetha, Natália Cruz-Martins, Biogenic Nanomaterials, 2023
Zahra Hajiahmadi, Reza Sayyad, Reza Shirzadian-Khorramabad, Devarajan Thangadurai
Uptake of ZnO NPs (8 nm, 500-4,000 mg/L) by seedling of soybean was appraised and dose-dependent uptake of ZnO NPs has been reported (Lopez-Moreno et al., 2010). Based on their results, the highest uptake efficiency of ZnO NPs was obtained at the concentration of 500 mg/L. Agglomeration of NPs at higher concentration (more than 1,000 mg/L) led to the hard passage of agglomerated NPs through cell wall pores. Uptake and translocation of CuO NPs by T aestivum (NPs<50 nm), Z. mays (NPs: 20-40 nm), and Phaseolus radiatus (NPs —30 nm) have been reported (Lee et al., 2008; Dimkpa et al., 2012; Wang et al., 2012b). Lee et al. (2008) evaluated the uptake of CuO NPs by root of P radiatus under in vitro conditions. They showed that the NPs entered the mung bean cells (Lee et al., 2008). Transportation of CuO NPs from root to shoot via xylem has been confirmed by Wang et al. (2012b) in maize plants. Lame et al. (2014) ascertained foliar uptake of silver NPs (Ag NPs) in lettuce plants. They sprayed Ag NPs (38.6 nm) on lettuce leaves and illustrated that Ag NPs passed through stomata and translocated to other parts of plants via vascular tissues (Lame et al., 2014). Passage of Ag NPs (-20 nm) through cell wall pores (5-20 nm) in Vigna radiata revealed that cell wall plays a sieve role and prevents larger NPs to enter plant cells (Mazumdar, 2014).
Evolution of Structures
Published in Stuart R. Stock, MicroComputed Tomography, 2018
Sintering of copper and steel (Distaloy AE) powders was also studied with synchrotron microCT, and changes in pore geometries in copper and elimination of very thin interparticle voids but not large pores in Distaloy were observed with increasing sintering time (Lame et al., 2003, 2004). Final dimensional changes are strongly anisotropic in Distaloy AE DensmixTM (axial swelling during delubrication and axial shrinkage during sintering), and repeated in situ synchrotron microCT observations during the different sintering stages (initial structure, lubricant burn-off, sintering, cooled structure) were used to investigate these changes (Vagnon et al., 2006). Analysis of the orientation distribution of three populations of pores (highly elongated, near circular, and intermediate geometry) was one probe; the second was an image correlation-based, local strain mapping comparison for the different directions in the compact.
Evolution of Structures
Published in Stuart R. Stock, MicroComputed Tomography, 2019
Sintering/cementation of powders has also been studied by microCT (Bernard, Vignoles et al. 2000, Lame, Bellet et al. 2003, 2004, Bernard, Gendron et al. 2005, Fu, Milroy et al. 2005, Pfister, Walz et al. 2005, Vagnon, Lame et al. 2006, Vaucher, Unifantowicz et al. 2007); research areas include analysis of rapid prototyped material and evolution of materials with nanoparticulate precursors. Bernard and coworkers employed local tomography to quantify porosity elimination and neck evolution in a glass powder and in a lithium borate powder over 1.6 × 104 s at 700°C and 720°C, respectively; growth of necks were particularly well illustrated by matched pairs of renderings, one showing the solid phase and the second the complementary void space (Bernard 2005, Bernard, Gendron et al. 2005). Topological evolution during sintering was described by Euler characteristics as a function of relative density (Okuma, Kadowaki et al. 2017). Sintering of copper and steel (Distaloy AE) powders was also studied with synchrotron microCT, and changes in pore geometries in copper and elimination of very thin interparticle voids but not large pores in Distaloy were observed with increasing sintering time (Lame, Bellet et al. 2003, 2004). Final dimensional changes are strongly anisotropic in Distaloy AE DensmixTM (axial swelling during delubrication and axial shrinkage during sintering), and repeated in situ synchrotron microCT observations during the different sintering stages (initial structure, lubricant burn-off, sintering, cooled structure) were used to investigate these changes (Vagnon, Lame et al. 2006). Analysis of the orientation distribution of three populations of pores (highly elongated, near circular, and intermediate geometry) was one probe; the second was an image correlation-based, local strain mapping comparison for the different directions in the compact.
Dispersion and attenuation of first and second sound waves under four models of Green-Naghdi generalized thermo-elasticity
Published in Waves in Random and Complex Media, 2021
Yueqiu Li, Yishuang Huang, Peijun Wei, Peng Zhang, Hong Wang, Junhua Du
In this numerical example, the metal copper is used to investigate the speeds and attenuation characteristics of two coupled thermo-elastic waves, i.e. CP wave and CT wave. The material constants of the metal copper are: Lame coefficients and ; The mass density ; The thermal capacity ; The thermal conduction coefficient which is associated with the temperature gradient is ; The thermal conduction coefficient which is associated with the thermal displacement gradients is assumed as ; the thermo-elastically coupled coefficient is , the phase-lag parameters for the three-phase-lag model are , and [26], respectively. The reference temperature is assumed as .