A tomographic heating holder for transmission electron microscopy that can be used to study supported catalysts at temperatures of up to ~1,500°C is described. The specimen is placed in direct thermal contact with a tungsten filament that is oriented perpendicular to the axis of the holder without using a support film, allowing tomographic image acquisition at high specimen tilt angles with min...

in present study we studied using green routes for microwave assisted synthesis of alumina nanoparticles from aluminum nitrate. it was revealed that when plant extracts are used, no specific stabilizer is needed. structural characterization of nanoparticles was studied using x-ray diffraction that showed semi-crystalline structure for two of plant extracts, other xrd patterns had no significant...

In the present investigation, γ-alumina nanoparticles with particle sizes less than 10 nm, high specific surface area (351 m2/g), high pore volumes and relatively narrow pore sizes distribution was prepared via sol-gel method in presence of aluminum isopropoxide as an aluminum precursor, distilled water, acetic acid as hydrolysis rate controller and tert-butanol as solvent. They had meso ...

The buoyancy-driven boundary-layer flow from a heated horizontal circular cylinder immersed in a water-based alumina (Al2O3) nanofluid is investigated using variable properties for nanofluid viscosity. Two different viscosity models are utilized to evaluate heat transfer enhancement from a cylinder. Exact analytic solutions of the problem are attained employing a novel...

Increasing uses of engineered nanoparticles (ENPs) in commercial products and industrial applications has eventually resulted to their releases into atmospheric, terrestrial, and aquatic environments. However, knowledge gaps in ENPs toxicity, fate, and behaviour currently limit our ability to quantify risk assessment of materials with nanoscale dimensions, and therefore, the extent of the resul...

Aluminium oxide (Al2O3), commonly known as alumina, is a widespread naturally occurring compound that has a broad range of industrial applications. Besides its use as a pigment or abrasive, alumina also plays a vital role as catalyst support for desulfurization or hydrogenation reactions. In the latter case, the active phase on the catalyst often consists of nickel metal nanoparticles. The inte...

Nanometer-sized functional particles are attractive for optical, electrical, magnetic, and biological applications. Recently, in addition to size, the shape of a nanoparticle was reported to be crucial, for example, to how it interacts with light, as presented by Halas and co-workers. They found that riceshaped nanoparticles made of gold and iron oxide are the most sensitive surface plasmon res...

A means for synthesizing paramagnetic nanoparticles composed of an Au–Fe alloy is described using pulsed laser deposition (PLD) of the alloy into a mesoporous alumina membrane template. Nanoparticles 46 ± 13 nm in diameter and composed of a 17% Fe alloy have been created by depositing a 35% Fe alloy into a template with 65 nm diameter pores. These paramagnetic nanoparticles had a saturation mag...

In this work, the desorption of furfural, which is a competitive intermediate during the production of biofuel and valuable aromatic compounds, was studied using pure alumina, as well as alumina impregnated with iron and platinum oxides both individually and in combination, using thermogravimetric analysis (TGA). The bimetallic sample exhibited the lowest desorption percentage for furfural. Hig...