To understand the origins of synchronous and asynchronous phase slippages observed in an array of apertures connecting two reservoirs of superfluid 4He, we have investigated the role of thermal fluctuations in the critical velocity and the possible effects of having an array rather than a single aperture through several model simulations. The results are compared with recent experiments carried...

Light transmission through circular subwavelength apertures in metallic films with surrounding nanostructures is investigated numerically. Numerical results are obtained with a frequency-domain finite-element method. Convergence of the obtained observables to very low levels of numerical error is demonstrated. Very good agreement to experimental results from the literature is reached, and the u...

Coded apertures may be designed to modulate the visibility between source and measurement spaces such that the position of a source among N resolution cells may be discriminated using logarithm of N measurements. We use coded apertures as reference structures in a pyroelectric motion tracking system. This sensor system is capable of detecting source motion in one of the 15 cells uniformly distr...

We propose a multi-aperture slow-light laser radar with two-dimensional scanning. We demonstrate experimentally that we can use two independent slow-light mechanisms, namely dispersive delay and stimulated Brillouin scattering, to dynamically compensate the group delay mismatch among different apertures, while we use optical phase locking to control the relative phases of the optical signals em...

Latest results of testing the compact dual bore quadrupole and sextupole represented. Dual bore quadrupole tested in cryostat up to ~150 A feeding current generating ~1 kG/cm in each aperture. Sextupole was tested in Dewar and able to generate ~0.7 kG/cm of integrated field. Transverse size of the magnets cold masses is about 180 mm. Dual bore water cooled room temperature apertures are 54 mm i...

A comparison is made between several scalar models for the formation of an image in a photoresist film with differing approximations and a vector model. It was found that up to numerical apertures of 0.7, a full scalar model showed no appreciable deviation from the vector model. However, when several common assumptions were made to simplify the scalar model, significant errors resulted at the h...

We present a brief historical overview of the classical theory of a radiating point charge, described by the Lorentz-Dirac equation. A recent development is the discovery of tunnelling of a charge through a potential barrier, in a completely classical context. Also, a concrete example is discussed of the existence of several physically acceptable solutions for a range of initial data. We end by...