High-resolution electron backscatter diffraction (EBSD) was used to examine the grain structure in long rods of ultrafine-grain (UFG) commercial-purity titanium produced for medical implants. The UFG material was obtained by equal channel angular pressing (ECAP) using a Conform scheme followed by rod drawing. The microstructure was found to be bimodal consisting of relatively coarse elongated g...

Ultrafine Si nanowires are grown on an Au/Si(111) substrate using gas source molecular beam epitaxy. These Si wires with crosssectional dimensions between 50 nm and 2 μm grow mainly with a growth axis parallel to the <111> direction. The growth rate of nanowires is independent of their diameters, i.e., nanowires with different diameters have the same growth rate. From the dependence of source g...

the formation of nano/ultrafine grained ferrite in low carbon steels containing different amounts of niobiumwas investigated using thermomechanical treatment which consisted of annealing of 85% cold rolled martensite with different parameters. the specimens were characterized by optical and scanning electron microscopy and vickers hardness test. a lamellar dislocation cell structure was formed ...

Ambient air pollution has been linked to exacerbation of cardiovascular disease morbidity and mortality. 1 These associations have been strikingly robust and range from the observation of coronary heart disease exacerbation within hours of exposure to an increased risk of ischaemic heart disease mortality for subjects chronically exposed to elevated concentrations of ambient particles. Two main...

This paper investigates the effects of surface modification of zinc borate ultrafine powders (ZB UFPs) on their tribological properties as lubricant additives in liquid paraffin (LP). ZB UFPs were successfully modified by hexadecyltrimethoxysilane (HDTMOS) and oleic acid (OA). It is evident that HDTMOS modified zinc borate ultrafine powder (HDTMOS-ZB UFP) delivered a small conglomerate size, go...

Al–Mg alloy powder was cryomilled to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic forging. The consolidation resulted in a bulk material with ultrafine grains of about 250 nm, and the material exhibited enhanced strength compared to conventionally processed Al–Mg alloy. The hardness of as-cry...

Heat and mass transfer between air and falling desiccant film is investigated for inclined parallel and counter flow configurations. Two different configurations are proposed and parametrically analyzed. Effect of inclination angle is examined to study enhancements in dehumidification and cooling processes of the air and regeneration of liquid desiccant in terms of pertinent parameters. Cu-ultr...

The ultrafine aerosol emitted by thermal spraying of metals using flame and electric arc processes has been characterized in terms of particle size distribution and emission rates based on both particle number and mass. Thermal spraying of Zn, Zn/Al, and Al was studied. Measurements taken using an electrical low pressure impactor and a condensation nucleus counter reveal an aerosol made up of v...