K m' m " iii " N = average protein concentration in resin at any time t , = initial solution protein concentration, mg/gm = initial resin protein concentration, mg/gm = final or equilibrium solution protein concentration, = final or equilibrium resin protein concentration, = protein concentration in solution at resin-solution in-= protein concentration in resin at resin-solution interface, = protein concentration in the solution that would be mg/gm mg/gm w / g m terface, mg/gm mg/gm equilibrium with the average particle concentration C at any time, mg/gm = protein concentration in resin that would be in equilibrium with bulk solution concentration, mg/gm = diffusion coefficient of protein in solution, cmz/s = diffusion coefficient of protein in r z i n , cm2/s = fractional conversion defined by (C(o) -C ) / ( c ( o ) = solution side mass transfer coefficient, cm/s = resin side mass transfer coefficient, cm/s = overall mass transfer coefficient defined by Eq. 1, cm/s = overall mass transfer coefficient defined by Eq. 20, cm/s = slope of a chord between a point defined by (C*, c) and a point at the intersection of aJne drawn from any operatin_g point (C, C ) with a slope equal to -k/k -C(m)) = (g-g / ( C = -C*) = ( C , -C * ) / ( C , -C ) = flux of protein, mg/cm2-s T O t = time, s V v 6 = effective resin particle radius, cm = amount of solution in stirred vessel, gm = amount of resin in stirred vessel, gm = effective solution film thickness, em A model is developed for pressure rise, extent of reaction and temperature changes during filling and curing in thin rectangular molds for the reaction injection molding (RIM) process. The predictions of the model are shown to be in good agreement with experimental results obtained for several intrumented molds using polyurethane RIM chemical systems. The relevant dimensionless groups are identified. Criteria for good mold filling are developed.The RIM process is a fairly new polymer processing method (Wood, 1974; Prepelka, 1979). Building on automotive success, it is moving into broader markets via improved systems which can give custom molding capability. The technique is still essentially an art and the trial and error approach employed in production often can not cope with variations in resin proper-J M. Castro 1s presently with the

We analyze the energy collection properties of holographic planar concentrator systems. The effects of solar variation on daily and annual energy collection are evaluated. Hologram diffraction efficiency, polarization, crosstalk in cascaded elements, and constraints imposed by the radiance theorem, as well as solar illumination characteristics, are considered. A planar holographic solar concentrator configuration is designed and modeled to maximize energy collection efficiency during the course of a year without the need for tracking. Results indicated that nearly 50% of the available energy illuminating hologram areas can be collected by photovoltaic cells without the need of tracking.

We experimentally demonstrate a novel grating which only produces reflection with mode conversion in a two-mode waveguide. That characteristic can improve the performance of optical devices that currently use tilted Bragg gratings to provide the mode conversion. Tilted Bragg gratings produce also reflections without mode conversion which increases noise and crosstalk of the optical device.

Because of its high strength‐to‐weight ratio, corrosion resistance, and low cost, Sheet Molding Compound (SMC) production offers great potential for growth in the automotive and trucking industry. Much attention is now being given to improving the economy of SMC compression molding by reducing the cycle time required to produce acceptable parts in steady production. One of the fastest‐growing applications of Sheet Molding Compound (SMC) compression molding panels is the manufacture of truck body panels. Owing to their large size, the molding forces developed are substantial and have a major influence in the molding cycle. The relevant process models for SMC flow are reviewed and a procedure is developed that can be used to obtain the closing force and calculate the needed material parameters. Experiments were done using commercially made SMC to verify the validity of this model and the compression force was predicted and compared to experimental values for commercially made automotive hoods.