Evaluating Positive and Negative Effects of Seven Biogenic Metal-based Nanoparticles on Seed Germination and Seedling of Nano-primed Wheat and Flax Seeds

Seed germination is the first and the most susceptible stage in plant’s growing phases, so could be considered as an index to evaluate the effect of newly developed materials like nanoparticles (NPs), providing useful information for researchers. In our experiments, germination tests have been carried out in Petri plates, containing wet filter paper and nano-primed seeds. We had biosynthesized seven nanoparticles in our previous researches, including calcinated and non-calcinated zinc oxide, zinc, magnesium oxide, silver, copper and iron nanoparticles. The effect of these biogenic nanoparticles and their counterpart metallic salts including zinc acetate, magnesium sulphate, silver nitrate, copper sulphate and iron (III) chloride was studied on two popularly grown plants, wheat and flax, in laboratory condition to obtain preliminary information for future field experiments. Germination percentage, shoot length, root length, seedlings length, root-shoot ratio, seedling vigor index (SVI), shoot length stress tolerance index (SLSI) and root length stress tolerance index (RLSI) were calculated at 2nd and 7th days of the experiment. According to the results, the response of the plants to metal containing nanoparticles and metal salts mainly depend on type of the metal, plant species, concentration of the NP suspension or salt solution, condition of the exposure and the stage of growth.

Investigation of Corrosion Resistance and Microstructural Performance of Zn-MgO-WB Composite Coating on Mild Steel

This Paper investigated the corrosion resistance and microstructural performance of zinc-magnesium oxide-tungsten boride (Zn-MgO-WB) composite coating on mild steel. Tungsten boride as an additive was co-deposited with zinc-magnesium oxide on mild steel via electrolytic deposition. The zinc-magnesium oxide and zinc-magnesium oxide-tungsten boride composite coatings were fabricated at the voltage of 0.6 and 0.8 V for 15 minutes and 45 °C. The effects of the deposits on the corrosion properties were examined. The corrosion behaviour was studied using linear polarization and weight loss method in 3.5% NaCl simulated environment. From the results obtained, it is evident that a decrease in applied potential influences the deposition of the coatings. The alloys with tungsten boride in their bath mixture performed better than those without. The zinc-magnesium oxide-tungsten boride (0.8 V) composite coated sample exhibits the least corrosion rate (Cr) of 0.0010482 mm/year and the microstructural examination of the sample via scanning electron microscope (SEM) unveiled homogeneous dispersion of particles and smooth morphology. The smooth morphology, defect-free surface, coupled with the uniform dispersion of the zinc-magnesium oxide-tungsten boride nanoparticles on the steel surface could have been responsible for high corrosion resistance performance of the coating in the simulated 3.5% NaCl medium. More so, the energy dispersive spectroscopy (EDS) revealed the presence of zinc, magnesium oxide, tungsten boride particles.

Development and Evaluation of qPCR Detection Method and Zn-MgO/Alginate Active Packaging for Controlling Listeria monocytogenes Contamination in Cold-Smoked Salmon

To answer to food industry requests to monitor the presence of L. monocytogenes in cold-smoked salmon samples and to extend their shelf-life, a qPCR protocol for the detection of L. monocytogenes, and an antibacterial active packaging reinforced with zinc magnesium oxide nanoparticles (Zn-MgO NPs) were developed. The qPCR allowed the sensitive and easy detection of L. monocytogenes in naturally contaminated samples, with specificity in full agreement with the standard methods. The halo diffusion study indicated a high antibacterial efficiency of 1 mg/mL Zn-MgO NPs against L. monocytogenes, while the flow cytometry showed only moderate cytotoxicity of the nanoparticles towards mammalian cells at a concentration above 1 mg/mL. Thus, the novel active packaging was developed by using 1 mg/mL of Zn-MgO NPs to reinforce the alginate film. Cold-smoked salmon samples inoculated with L. monocytogenes and air-packed with the Zn-MgO NPs-alginate nanobiocomposite film showed no bacterial proliferation at 4 °C during 4 days. In the same condition, L. monocytogenes growth in control contaminated samples packed with alginate film alone. Our results suggest that Zn-MgO nanoparticles can extend the shelf-life of cold-smoked salmon samples.

A steady-state and transient analysis of the electron transport that occurs within bulk wurtzite zinc-magnesium-oxide alloys subjected to high-fields

ABSTRACTWe present some recently acquired results corresponding to the nature of the electron transport that occurs within bulk alloys of zinc-magnesium-oxide. These results are obtained using three-valley ensemble semi-classical Monte Carlo electron transport simulations. The impact that the magnesium content plays in shaping the form of the electron transport related characteristics associated with this alloy system is explored. Both steady-state and transient electron transport results are examined. The device implications of these results are then commented upon.