[en] Vignettes of the history of nuclear energy in Canada, from its wartime beginnings to Douglas Point, are recounted, with emphasis on the NRX reactor

[en] Short communication

[en] This paper reports that over the previous years with the introduction of more strict regulations and guidelines on the national, state, and local level, there has been a relatively high state of confusion regarding aboveground tank inspection. During this time inspections must continue for the good of the overall operation yet we are constantly being bombarded by new and rumored regulations, inspection techniques, and equipment ideas. With the First Edition in January 1991 of API 653, clarification was given the owner/operator, inspection companies and all others associated with tankage direction to insure the overall safe operation of the aboveground storage tank. This edition provides only the minimum requirements. Explored are additional methods of inspection such as visual, magnetic particle, ultrasonic, radiography, acoustic emissions, as well as final engineering evaluation to assist the owner/operator to make a confident decision on the integrity of tankage. This would be of interest to petroleum engineers

[en] Our purpose was to evaluate the effects of ovariectomy in conjunction with cadmium (Cd) exposure on bone. Aged female beagles with ⁴⁵Ca-labeled skeletons ovariectomized and exposed to Cd. Successive vertebral scans by dual photon absorptiometry monitored changes in bone mineral density (BMD) in each dog with time. Results showed that ovariectomy or Cd exposure alone caused significant decreases in BMD; ovariectomy with Cd exposure caused the greatest decrease. Ovariectomy alone did not decrease BMD in the distal end or mid-shaft of the tibia while BMD of the distal tibia decreased significantly due to Cd exposure alone. Combination treatment resulted in significant decreases in BMD of both tibial regions. At necropsy, tibiae, humeri, lumbar vertebrae and ribs were obtained for biochemical analysis. No group-to-group differences in bone weights (wet, dry, ash), in ash/dry ratios, or in long bone and vertebral Ca/dry or Ca/ash ratios were observed. Significantly higher total ⁴⁵Ca content and ⁴⁵Ca/dry and ⁴⁵Ca/ash ratios were observed in long bones and vertebrae of OV- and OV+ groups. In contrast, intact ribs showed significantly decreased Ca/dry and Ca/ash ratios compared to the SO-group. Quartered ribs demonstrated regional responses to specific treatment; decreases in total Ca content were greatest in the mid-rib region (-36 to -46%). Results suggest that in the aged female beagle, bone mineral loss associated with estrogen depletion is not only related to bone type (trabecular versus cortical) but also to bone Ca pools. Our results also suggest that a regional heterogeneity of bone plays a role in responsiveness to ovariectomy and Cd exposure. These aspects suggest that Cd is an exogenous factor affecting bone mineral loss independently of estrogen depletion. However, estrogen depletion primes bone for responsiveness to Cd-induced bone mineral loss