Stress Inducible Overexpression of AtHDG11 Leads to Improved Drought and Salt Stress Tolerance in Peanut (Arachis hypogaea L.)

Peanut is an important oilseed and food legume cultivated as a rain-fed crop in semi-arid tropics. Drought and high salinity are the major abiotic stresses limiting the peanut productivity in this region. Development of drought and salt tolerant peanut varieties with improved yield potential using biotechnological approach is highly desirable to improve the peanut productivity in marginal geographies. As abiotic stress tolerance and yield represent complex traits, engineering of regulatory genes to produce abiotic stress-resilient transgenic crops appears to be a viable approach. In the present study, we developed transgenic peanut plants expressing an Arabidopsis homeodomain-leucine zipper transcription factor (AtHDG11) under stress inducible rd29A promoter. A stress-inducible expression of AtHDG11 in three independent homozygous transgenic peanut lines resulted in improved drought and salt tolerance through up-regulation of known stress responsive genes (LEA, HSP70, Cu/Zn SOD, APX, P5CS, NCED1, RRS5, ERF1, NAC4, MIPS, Aquaporin, TIP, ELIP) in the stress gene network, antioxidative enzymes, free proline along with improved water use efficiency traits such as longer root system, reduced stomatal density, higher chlorophyll content, increased specific leaf area, improved photosynthetic rates, and increased intrinsic instantaneous WUE. Transgenic peanut plants displayed high yield compared to non-transgenic plants under both drought and salt stress conditions. Holistically, our study demonstrates the potentiality of stress-induced expression of AtHDG11 to improve the drought, salt tolerance in peanut

Mechanical properties of equal channel angular extruded magnesium boride (MgB2) powder in tubes (PITs)

The MgB2 PITs, prepared by filling Fe tubes with MgB2 as a core, were processed through different number of passes at room temperature via Routes A, B-A, C and BC. The mechanical properties of the PITs were measured in terms of density and hardness. The extent of the compaction was also studied through shear punch test. The shape of the compacts remains circular even after four passes via Route C & B-C. Higher density and hardness along with higher USS is observed from the PITs of Route C compared to Route BC. The PITs processed through Route A and Route BA did not show sufficient compaction to carryout the density measurements. Thus, the current study shows that Route C is the optimal route; to attain good mechanical proper-ties in ECAE processed MgB2 PITs with Fe tube

Multipass equal channel angular extrusion of MgB2 powder in tubes

In the current study multipass equal channel angular extrusion (ECAE) is adopted for the first time to study the applicability of the process to compact magnesium boride (MgB2) Powder in tubes (PITs). The influence of number of ECAE passes on MgB2 PITs was also analyzed in terms of microstructure, density and mechanical properties. MgB2 PITs with iron tube were processed up to six ECAE passes. X-ray analysis of the compacts showed no other phases, other than MgO, in MgB2 compacts even after large mechanical working and annealing. Simple shear stresses predominant in ECAE constantly rendered compaction of the hard brittle MgB2 powders. (c) 2007 Elsevier B.V. All rights reserved

MnCo2O4 nanosphere synthesis for electrochemical applications

The present work addresses the important need of new materials to improve energy storage materials. The synthesis of MnCo2O4 nanospheres by employing solvothermal method at different incubation times was carried out. The effects of reaction time on structural, morphological, and electrochemical studies were briefly investigated. The X-ray diffraction result unveils the formation of cubic-structured MnCo2O4 nanospheres with Fd3m (2 2 7) space group. The appearance of two Raman peaks at 480 and 662 cm−1 was greatly attributed to the stretching vibration mode of M–O (M = Mn, Co), and substantiates the formation of MnCo2O4. The presence of functional group and characteristics group was analyzed by Fourier-transform infrared spectroscopy. The scanning electron microscope image clearly indicated different sizes of nanoparticles due to the effect of solvothermal reaction period. The energy storage behavior of MnCo2O4 nanospheres was studied by employing the cyclic voltammetric and charge–discharge cycles. The results confirmed the pseudocapacitive nature of MnCo2O4 nanoparticles (RF3) with porous, spherical nanostructure with larger radius than others and contribute to better specific capacitance of 252 F g−1 at current density of 1 A g−1 which could be considered as a potential candidate for pseudocapacitive electrode for energy storage devices. Keywords: Cubic, MnCo2O4, Nanospheres, PVP, Fd3m (2 2 7) space group, Energy storag

Shear punch tests for a bulk metallic glass

Abstract A shear punch test technique was used for characterization of the mechanical properties of Zre5Tie17.9Cue14.6Nie10Al bulk metallic glass. The ultimate shear stress values matched very closely with values derived from uniaxial compression tests reported in the literature. This is consistent with a lack of pressure sensitivity in compression reported for this particular metallic glass. Deformation response was strain rate insensitive up to a critical rate, beyond which softening occurred. The latter was attributed to thermal heating effects

Finite element analysis of a shear punch test

The authors present new experimental data for shear punch tests and tensile tests using four different materials. The correlation between shear punch and tensile yield stresses must be established empirically, and the procedure for doing this is discussed. The elastic-plastic deformation in a shear punch test develops gradually with increasing punch displacement and is often assumed to be simple shear. This is examined using finite element analysis to simulate the development of plasticity during the early stages of punch displacement. The simulation results are used to rationalize the empirically established yield stress correlations