Atmospheric cloud condensation nuclei (CCN) concentrations are a key uncertainty in the assessment of the effect of anthropogenic aerosol on clouds and climate. The ability of new ultrafine particles to grow to become CCN varies throughout the atmosphere and must be understood in order to understand CCN formation. We have developed the Probability of Ultrafine particle Growth (PUG) model to ans...

The present work was undertaken to improve superplastic ductility of friction-stir welded joints ultrafine-grained (UFG) Al–Mg–Sc–Zr alloy. In order suppress the undesirable abnormal grain growth, which typically occurs in heavily deformed base material, UFG material produced at elevated temperature. It suggested that new processing route could reduce dislocation density structure and thus enha...

Studies into the effects of ultrafine particles in the lung have shown adverse effects considered to be due in part to the particle size. Air pollution particles (PM(10)) are associated with exacerbations of respiratory disease and deaths from cardiovascular causes in epidemiological studies and the ultrafine fraction of PM(10) has been hypothesized to play an important role. The aim of the pre...

Inhalation of Rn progeny has been recognized as a health risk, primarily as a cause of human lung cancer. Rn progeny in the domestic environment contributes the greatest fraction of the natural radiation exposure to the public. The ultrafine activity of these progeny amounts up to about 10 percent of the total activity (attached and ultrafine), but is considered to yield about 50 percent of the...

Abstract. Grain boundary sliding plays a key role on the high temperature deformation of fine grained materials. This mechanism is related to strain rate sensitivity approximately 0.5 and usually gives rise superplastic elongations. The controlling equation for grain has shown good agreement with experimental data multiple materials, different sizes tested at rates. However, predictive ability ...

Studies with intravenously injected ultrafine particles have shown that the liver is the major organ of their uptake from the blood circulation. Measuring translocation of inhaled ultrafine particles to extrapulmonary organs via the blood compartment is hampered by methodological difficulties (i.e., label may come off, partial solubilization) and analytical limitations (measurement of very smal...

Recent discovery that nanoscale twin boundaries can be introduced in ultrafine-grained metals to improve strength and ductility has renewed interest in the mechanical behavior and deformation mechanisms of these nanostructured materials. By controlling twin boundary spacing, the effect of twin boundaries on void growth is investigated by using atomistic simulation method. The strength is signif...

Ultrafine elongated grain (UFEG) structure with a strong <110>//rolling direction fiber texture was created for 0.4%C-2%Si-1%Cr-1%Mo steel (mass%) through deformation of tempered martensite using multi-pass caliber rolling at 773 K reduction 78% (i.e. warm tempforming). Annealing the tempformed 843 enhanced delamination toughening lower temperatures without significant loss tensile strength 1.8...

Cobalt-based superalloys are common materials for the manufacturing of various components used in aerospace applications. Conventional cobalt-based with a unimodal grain structure generally exhibit low strength and ductility at high temperatures. A bimodal superalloy, Co–20Cr–15W–10Ni (CCWN), was designed to achieve both The deformation behavior tensile properties CCWN alloy fine-grain (FG), co...