Electro-optic spectral shearing interferometry is implemented for the highly sensitive characterization of ultrashort pulses from a free-running source. A simple phase-locked-loop clock recovery circuit is used to extract the high-frequency microwave clock signal to drive the phase modulator for spectral shearing. We demonstrate accurate full temporal characterization of 200-fs pulses from an o...

The role of the liquid-crystal layer in the phase-shifting shearing interferometer that was proposed by Griffin [Opt. Lett. 26, 140 (2001)] is analyzed. An extra voltage-dependent phase difference is produced when the phase retarder is oriented at an angle from the optical axis of the laser beam such that the interferogram will not repeat itself after a 2pi phase change of the liquid-crystal re...

We run mean-field shearing-box numerical simulations with a temperaturedependent resistivity and compare them to a reduced dynamical model. Our simulations reveal the co-existence of two quasi-steady states, a ‘quiet’ state and an ‘active’ turbulent state, confirming the predictions of the reduced model. The initial conditions determine on which state the simulation ultimately settles. The acti...

We propose a new model for {001} platelets in diamond based on the formation of a metastable stacking-fault. The core of the defect is a double layer of threefold coordinated sp2 carbon atoms embedded in the sp3 diamond matrix. The properties of the model were determined using ab initio calculations. All significant experimental signatures attributed to the platelets are fully accounted for. Th...

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wavefront distortions. It is used in astronomical telescopes and laser communication systems to remove the effects of atmospheric distortion. An AO system basically consists of three main components, a wavefront sensor, a wavefront corrector and a control system. A new wavefront sen...

Shearing ewes in mid pregnancy can provide farmers with management and financial advantages. Six experiments conducted at Massey University have collectively shown that shearing ewes at this time can increase lamb birthweight by up to 1.0 kg. When comparisons were made across studies, there was a strong negative relationship between size of the response and the birthweight of control lambs (tho...

Cropping is a cutting process whereby opposing aligned blades create a shearing failure by exerting opposing forces normal to the surfaces of a metal sheet or plate. Building on recent efforts to quantify cropping, this paper formulates a plane strain elastic–plastic model of a plate subject to shearing action by opposing rigid platens. Shear failure at the local level is modeled by a cohesive ...

The degradation stability towards mechanical shearing (shear stability) of poly(methyl methacrylate) (PMMA) and its copolymer with styrene at different level of concentrations have been investigated. With a view to understanding the relationship between the thickening performance (percent increase in viscosity of the solvent in the additive of the unit weight of polymers) and shear stability of...