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The environmental stress such as, salinity (soil or water) and drought are serious obstacles for horticulture and field crops in further areas of the world, especially arid and semiarid regions. In order to investigate salinity and drought stress on fenugreek germination indices, an experiment was carried out. To create salinity stress, sodium chloride (NaCl) at the levels of 0 (as control),-3,-6 and-9 bar, and for drought stress, polyetylenglycol 6000 (PEG 6000) in osmotic levels at 0 (as control),-3,-6 and-9 bar were used. Result showed significance different between evaluated indices. Increasing of stress levels lead to reduction of germination and epicotyls and hypocotyls length. Also, both salinity and drought at-9 bars cause reduction in germination and growth indices, however, a few of the seeds conserved germination viability. Therefore, fenugreeks have relative resistance to salinity and drought stress in germination stage.

A hollow circular cylinder made of exponentially graded piezoelectric material, such as PZT_4, is considered. Loading is composed of internal and external pressures, a distributed temperature field due to steady state heat conduction with convective boundary condition, an inertia body force due to rotation with constant angular velocity and a constant electric potential difference between its inner and outer surfaces. The material properties except Poisson's ratio and thermal conduction coefficient are assumed to be exponentially distributed along radius. The governing equation in polarized form is shown to reduce to a second-order ordinary differential equation with variable coefficients for the radial displacement. In this article, a closed form solution is presented for this ODE by employing hypergeometric functions such as Whittaker's M and W functions. Also we have considered four different sets of boundary conditions. The electrothermomechanical induced stresses and the electric potential distributions are investigated for the piezoceramic PZT_4 cylinder. It is concluded that the inhomogeneity exponent µ plays a substantial role in radial and circumferential stress distributions. Therefore, the results of this investigation can contribute to the design of EGPM rotating thick-walled circular cylinders.A list of symbols can be found on page 881.