The dielectric permittivity, conductivity and loss tangent of water were measured with non-blocking electrodes for different thicknesses of the sample and for various oscillator levels. The measurements were carried out in the 20-90°C temperature range with the 10°C interval. Domain Debye resonances in water, as well as changes in dielectric constants, relaxation times and conductivity with tem...

Gas bubbles in water act as oscillators with a natural frequency inversely proportional to their radius and a quality factor determined by thermal, radiation, and viscous losses. The linear dynamics of spherical bubbles are well understood, but the excitation mechanism leading to sound production at the moment of bubble creation has been the subject of speculation. Experiments and models presen...

increasing the thermal stability and resistance to bacterial attack (bioresistance) of the potato starch used in the water-based drilling fluid is the aim of this work. four types of potato starch grafted with acrylamide and a mixture of each one with acrylic acid, 2-acrylamido-2-methyl-1-propane sulfuric acid and itaconic acid were synthesized by manganese (iv)-induced redox system at the suit...

We present an analytical model and numerical experiments to describe optimal bistable switching in a nonlinear photonic crystal system. It is proved that only three parameters are needed to characterize a bistable switch: the resonant frequency omega(res), the quality factor Q, and parameter kappa that measures nonlinear "feedback strength." A photonic crystal enables the device to operate in s...

abstract- to investigate the effect of draught stress on water relations, stomatal density, chlorophyll content and yield of rapeseed, an experiment was done with four levels of drought stress including l1 (field capacity, fc), l2 (70% available water content, awc), l3 (50% awc), and l4 (30% awc), within three growth stages- including stem elongation (t1), onset of flowering (t2) and silique fo...

wheat, cv. alvand, under late sowing condition and comparison with conventional sowing date was investigated in a field experiment in 2009-2010. the factors were seven levels of priming by sa, including control or untreated seeds, 400, 800, 1200, 1600, 2000 and 2400 µm sa and two sowing dates including conventional sowing date (23 october) and late sowing (22 november). results showed that prim...

In this work, we demonstrate ultra-low-threshold, optically pumped, room-temperature lasing in GaN microdisk and micro-ring cavities containing InGaN quantum dots and fragmented quantum wells, with the lowest measured threshold at a record low of 6.2  μJ/cm2. When pump volume decreases, we observe a systematic decrease in the lasing threshold of micro-rings. The photon loss rate, γ, increases w...