Cracking is a major concern in welding aluminum alloys. Although weld solidification cracks can be eliminated through addition of filler alloy, the additives modify the alloy or base-metal constituents and may not always be desirable. High-energy beam processes, such as electron-beam welding, that result in minimal heat input reduce crack sensitivity, but their high cost limits their applicatio...

Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges—bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks wit...

Tropospheric ozone is increasing at a fast pace and causes large losses of production in cultivated plants and forests (UNECE, 2004). Ozone risk assessment has been based for a long time on exposure to external ozone concentration. Doses above a selected threshold (generally 40 nL L) have been considered injurious, and the cumulated exposure to these concentrations has been the basis of the lev...

Not much has been written about air cleaning from ozone. The aim of this paper was to demonstrate the possibility of adsorption air cleaning from ozone. The second aim was to investigate the dependence of the efficiency of ozone removal from the air on the height of the adsorber layer and on concentrations of ozone, and to obtain empirical formulas for calculating the efficiency of ozone treatm...

First year university science students are surveyed about their understanding of the ozone layer, ozone depletion and the effect of ozone depletion on Australia. Although students seem to understand the basic function of the ozone layer, over 65% of students incorrectly believe that the ozone hole is over Australia, and over 90% of students incorrectly believe that the ozone hole is present dur...

[1] Changes in the variability of surface ozone can affect the incidence of ozone pollution events. Analysis of multi-century simulations from a chemistry climate model shows that present-day summertime variability of surface ozone depends strongly on the jet stream position over eastern North America. This relationship holds on decadal time scales under projected climate change scenarios, in w...

Ozone is well known as a powerful, fast reacting oxidant. Ozone based processes produce no by-product residual as non-reacted ozone decomposes to molecular oxygen. Therefore an application of ozone is widely accepted as one of the main approaches for a Sustainable and Clean Technologies development. There are number of technologies which require ozone to be delivered to specific points of a pro...

We examined the physiological response of foliage in the upper third of the canopy of 125-year-old giant sequoia (Sequoiadendron giganteum Buchholz.) trees to a 61-day exposure to 0.25x, 1x, 2x or 3x ambient ozone concentration. Four branch exposure chambers, one per ozone treatment, were installed on 1-m long secondary branches of each tree at a height of 34 m. No visible symptoms of foliar oz...

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. Tube growth rates in the presence of a range of ozone dosa...