Roger E. Eckert

Sequential design of initial experiments for chemical kinetic modeling-isomerization of n-pentane

Abstract A procedure for the sequential design of experiments for model discrimination and precise parameter estimation is presented and applied to the published example of isomerization of n -pentane. The present paper outlines a method for designing the preliminary experiments which were chosen arbitrarily by the earlier workers. The procedure leads to selection of the correct model for all the cases considered here. Well-designed initial experiments improve the degree of precision in parameter estimation also.

Effect of film processing on cryogenic properties of poly(ethylene terephthalate)

Abstract The effects of stretch temperature, heat-set temperature, and heat-set time on the cryogenic mechanical properties of PET film were studied by using a two-level factorial experiment. Squares of amorphous PET sheet were given a simultaneous biaxial 3x stretch in a laboratory film stretcher at either 85 or 95°C. The levels of heat-set temperature and time investigated were 190 and 210°C and 15 and 120 sec, respectively. Crystallinities of the films were determined by the density-gradient technique. Tensile properties were measured in liquid nitrogen (77°K) and liquid hydrogen (20°K). Biaxial burst properties were obtained in liquid nitrogen. It was found that processing variables significantly affect the stress-strain properties of PET film at cryogenic temperatures. These results and encouraging values of flexibility offer leads for possible use of specially processed PET films for cryogenic space applications.