Engineering topics
Publications and source records attributed to Crawford, R. G..
Experiments performed on the heat resistant organism CK 4-6 are described. Its response to dry heat at two temperatures (125 C and 135 C) at eight humidity levels (0.001 percent to 100 percent RH) in a closed can system is studied.
The thermal resistance of vegetative cells in the percent RH range of 0.19 to 100 at 60 C was investigated. Staphylococcus aureus was used in the experiment because of the extension of the moisture range that can be examined.
Dry heat sterilization of spacecraft was investigated by studying the production of spore crops, and thermal inactivation of the spores, and bacillus subtillus. Spore assays were made by conventional plate count methods, and survival curves for the spores are presented. The results indicate that the inherent resistance of spores from a parent cell can be maintained.
The mechanism for thermal inactivation of bacterial spores under moist or dry heat was studied. Experimental conditions were established relating to spore loss of heat resistance and loss of optical density as a measure of the rate and extent of germination in spore suspensions. Events occurring during germination were correlated with phase darkening (refractility and non-refractility of spores), stainability characteristics of heat and non-heat treated spores, morphological characteristics, and studies on swelling of spores by an increase in packed cell volume.
Thermal environment effects on alignment behavior of structural joints and assemblies of reentry vehicle and Mars landing module
Saturn launch vehicle systems in terms of design, operating characteristics and potential applications, showing need for reusable space shuttle systems
Axially loaded cylindrical structures analyzed for optimum weight construction consistent with cost constraint, emphasizing beryllium-aluminum alloys
Thermal sterilization environment as significant design condition for planetary lander entry-shield bond-structure combination
Axially loaded cylindrical structures analyzed for optimum weight construction consistent with cost constraint, emphasizing beryllium-aluminum alloys
Design criteria for planetary spacecraft subject to heat sterilization
Recovery of bacteria, bacillus globigii spores from balsa wood and soluble plastic and toxicity of plastics - contamination studies