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RHEA is a single-modeéchelle spectrograph designed to be a replicable and cost effective method of undertaking precision radial velocity measurements. The instrument has a novel fiber feed with an integral field unit injecting into a grid of single-mode fibers reformatted to form a pseudo-slit, increasing throughput and enabling highspatial resolution observations when operating behind Subaru and the SCExAO adaptive optics system. The past 18 months have seen a replacement cable constructed for the instrument to address modal noise caused by closely packed fibers with similar path lengths. Here we detail the cable fabrication procedure, design improvements, increased precision in meeting the required sub-micron optical tolerances, throughput gains, and known remaining issues.

The aim of this paper is to demonstrate that a simple stirred batch cell can be used to study the effects of surface shear stress (amongst other process parameters) on fouling from saturated calcium salt solutions. For otherwise identical operating conditions, the overall fouling rate on a smooth mild steel surface was found to be reduced when either fine wires were attached to it or when helical threads were incorporated into the surface, either in the form of a continuous helical groove or in the form of a raised helix. The raised helical surface was more effective in reducing fouling than the helical groove. The results confirm the general effect that fouling rates can be reduced by increasing the surface shear stress through surface enhancement. A simple mathematical model has been developed to take into account the dynamic change in bulk concentration as crystallization fouling occurs. In all cases, the overall fouling resistance increased asymptotically towards a constant value and could easily and accurately be described quantitatively by the new analytical model. The variations of shear stresses on the various surfaces were determined from CFD simulations using the commercial package Comsol 4.2.

The following are summaries of three of the Plenary Lectures presented a t a Colloquium of the Particle Size Analysis Group held on September 13th and 14th, 1972, and reported in the November, 1972, issue of Proceedhzgs (p. 232).