Showing 3 results for Mg
Volume 8, Issue 2 (10-2009)
Abstract
Maize seedlings were treated with various concentrations of copper (25-100 µM) without EDTA and with EDTA for 120 hours. A sever and progressive decrease of root length and dry weight and an increase in K+ leakage with increasing Cu in nutrient solution was observed in the treated plants with Cu without EDTA. The roots accumulated significantly higher amounts of Cu than the shoot. With increasing Cu concentrations, amounts of Ca, Mg, K and Fe decreased in roots and in shoot. Application of EDTA with Cu caused increased dry weight and root length but decreased K+ leakage into nutrient solution. Application of EDTA increased Cu accumulation in roots but decreased it in shoot and caused a different effect on other minerals contents. Overall, EDTA could reduce copper toxicity in Maize seedlings.
Volume 9, Issue 4 (10-2010)
Abstract
Many investigations have been carried out to produce ectomycorrhizas on the growth and nutrent absorption of plants. However, no investigations has been carried out on the effect of ectomycorrhizas on nutrient contents of pistachio Badamy, when mycorrhzal (M) and Non-mycorrhizal (NM) plants exposed to different amounts of Mg. To study the resistance role of ectomycorrhizal Pistachio plants exposed to excess Mg, mycorrhizal (M) and Non-mycorrhizal (NM) plants of pistachio var Badami were grown at axenic condition and were treated with different levels of Mg (MgSo4) prepared as a Hogland nutrient solution with 1/2 concentration. The colonization rates of the plants with Agaricus bisporus and mineral nutrient contents in roots and shoots were measured and statistically compared. The results showed the increasing of mycorrhizal colonization as Mg increased in the medium. Mycorrhizal plants had higher Mg, Ca, P, k, Fe, Na, Mn, Zn, Cu contents at high levels of Mg treatment. At low amounts of Mg, K, Fe, Mn, Cu contents of NM plants were higher than M plants.
Farhad E.ghodsi, , ,
Volume 12, Issue 4 (11-2013)
Abstract
MgO thin films were prepared using sol-gel method. The influence of annealing temperature on optical, structural properties and surface morphology of the films were investigated using FTIR, UV-Visible and photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The optical constants and thickness of the films were determined by pointwise unconstrained minimization approach. The optical transmittance has decreased with increase of annealing temperature. The refractive index and extinction coefficient of the films increased while the thickness and optical band gap of the films decreased with increasing of annealing temperature. The thickness of film decreased from 635 to 420nm and optical band gap decreased from 4.05 to 4.02eV. The photoluminescence (PL) intensity increased with annealing temperature. XRD patterns demonstrated that the prepared films at 500℃ were amorphous. In addition, the crystal structure of MgO nanopowders which was prepared by sol-gel method was investigated. The crystalline orientation of MgO nanopowders was improved by increasing the sintering temperature. The SEM micrographs show that a homogenous and crack-free film can be prepared at 500°C.
