Effect of gas bubbles on recrystallization of tungsten

Tungsten sheet deposited from WF₆ vapor was rolled at temperatures up to 1000°C and reductions in thickness up to 95 pct. Recovery and recrystallization were studied using hardness measurements and transmission electron microscopy. The temperatures for the onset of recrystallization during 1 hr anneals were 1600°C or more. Recrystallization was sluggish, requiring temperatures of 2100°C or more for completion. Transmission electron microscopy revealed that many small (< 500Å diam) gas bubbles were present on dislocations and recovered subgrain boundaries and caused scalloping of these boundaries and the advancing recrystallized grain boundaries. Coarsening of the bubbles to a relatively few larger bubbles permitted complete recrystallization. No solid inclusions were found. Annealing treatments that coarsened the gas bubbles prior to rolling caused accelerated recovery and complete recrystallization was observed at approximately 1200°C. It is concluded that small gas bubbles were the cause of the original high recrystallization temperatures and also influenced the size and shape of the recrystallized grains.     

Sterilization of Ground Prepacked Indian Spices by Gamma Irradiation

Prepacked ground Indian spices which included pepper. turmeric, chilli, and coriander were found to be heavily contaminated with bacteria and molds. The total bacterial counts ranged between 10⁵–10⁷. whereas total fungal counts ranged between 10²–10⁶. Red chilli was found to be the most contaminated spice. The bacterial population consisted mainly of spores. A dose of 10 kGy was found to be effective in destroying these microbes in prepacked spices without affecting their quality attributes. To eliminate mold contamination a dose of 5 kGy was sufficient. During a six-month storage study of irradiated and unirradiated spices, the irradiated spices were found to retain their quality.     

STARCH TRANSFORMATION DURING BANANA RIPENING: I — THE PHOSPHORYLASE AND PHOSPHATASE BEHAVIOR IN MUSA ACUMINATA

Starch levels as well as the phosphorylases and acid phosphatase activity during ripening of the banana fruit was investigated. The concentrations and sequence of appearance of sucrose, glucose and fructose were determined by use of specific enzymatic reactions. During the climacteric period, the phosphatase activity increased while phosphorylase activity, which initially increased before starch transformation began, thereafter decreased in a complex pattern. The starch was transformed into sucrose with later formation of glucose and fructose. Four bands of phosphorylase multiple forms, detected electrophoretically, did not change during ripening. One of them was able to synthesize a branched starch-using amylose as a primer and glucose 1 -phosphate as the substrate. Banana slices were infiltrated with water or solutions of cycloheximide or actinomycin D. Inhibition of phosphatase-induced activity was recorded only in the cycloheximide group. No change in phosphorylase activity was detected in any of these infiltrated groups. Sucrose production from starch was partially inhibited both by actinomycin D and cycloheximide. The aformentioned results were interpreted as indicating the previous presence of phosphorylase in the preclimacteric phase without new synthesis during ripening. The increase of activity of phosphatase was probably due to ribosomal synthesis rather than to nucleic acid synthesis.     

EFFECT OF SEASONAL VARIATIONS ON PROTEIN FUNCTIONAL PROPERTIES OF FISH DURING FROZEN STORAGE

Influence of seasonal variation (February, July and October), time elapsed before freezing, and type of processing of the muscle on several functional properties (protein solubility, emulsifying capacity, and viscosity) in two species of fish with differing seasonal behavior (hake and sardine) were studied. Correlations between the changes in these functional properties during frozen storage were established. Although proximate analyses of the hake muscle were similar throughout the year, significant differences were observed in viscosity and protein solubility during storage between lots of fish caught in different seasons. Changes in the functional properties were less evident in sardine, which undergoes wide seasonal variations. The larger differences in the functional proprities of hake muscle, depending on season, were related to differences in the dimethylamine content after the fifth month of frozen storage. High correlations were established between functional properties in fish caught in the same or different seasons. Any of the three functional properties studied can be used as a suitable index of the quality of frozen fish, irrespective of the different conditions studied.     

Individual perceptions of community resilience following the 2011 Joplin tornado

Approximately 6–7 months after the deadliest tornado in the United States since 1947, we conducted a RDD telephone survey of Joplin residents (N = 380) to examine perceptions of community resilience (CR). We found that participants had positive perceptions of the resilience of their community after this major disaster. Older participants were more likely to perceive the community to be resilient than younger participants. More tornado experience was related to lower perceptions of CR. More use of traditional media (television and newspapers) for tornado information and more conversation with friends, family and neighbours about the tornado was associated with higher CR perceptions. Overall, mediated and interpersonal communication processes appear important for fostering CR following a major disaster.