We have measured the growth kinetics of gold nanoparticles in real time. Gold nanoparticles were formed from the reduction of gold (III) in aqueous solution and monitored with a stopped-flow reactor equipped with a diode array. The overall reduction of gold (III) occurred in less than 20 [ms]. The growth kinetics was determined from measurements of the plasmon resonance time-dependent wavelengt...

We briefly describe a model which seems to be applicable to a variety of coalescence growth systems. Spanning cluster growth, particle growth and hillockformation in thin metal f%ns, this model is based on the Smoluchowski kinetic equations and fractals. We describe how this model has been able to suggest the e$ect of translational to internal energy conversion in coalescing systems in determin...

[1] Vertically pointing Doppler radar has been used to study the evolution of ice particles as they sediment through a cirrus cloud. The measured Doppler fall speeds, together with radar-derived estimates for the altitude of cloud top, are used to estimate a characteristic fall time tc for the ‘average’ ice particle. The change in radar reflectivity Z is studied as a function of tc, and is foun...

We report an epitaxial growth technique for scalable production of hybrid sodium rare-earth fluoride (NaLnF4 ) microcrystals, including NaYF4 , NaYbF4 , and NaLuF4 material systems. The single crystalline nature of the as-synthesized products makes them strong upconversion emission. The freedom of combining a lanthanide activator (Er(3+) or Tm(3+) ) with a sensitizer (Yb(3+) ) at various doping...

Magnetite (Fe3O4) nanoparticles were synthesized by coprecipitation route. Coprecipitation is a simple, reproducible and accessible technique relying on the coprecipitation of Fe2+ and Fe3+ cations by NaOH as base at low temperature (~80 °C). In this work, the role of different solvents (H2O, ethylene glycol, diethylene glycol, triethylene glycol) on phase, structure, microstructure and magneti...

This work examines the effect of direct radiative forcing of aerosols in the eastern Mediterranean troposphere as a function of air mass composition, particle size distribution and hygroscopicity, and relative humidity (RH). During intensive field measurements on the island of Crete, Greece, the hygroscopic properties of atmospheric particles were determined using a Hygroscopicity Tandem Differ...

A major source of particle number emissions is road traffic. However, scientific knowledge concerning secondary particle formation and growth of ultrafine particles within vehicle exhaust plumes is still very limited. Volatile nanoparticle formation and subsequent growth conditions were analyzed here to gain a better understanding of "real-world" dilution conditions. Coupled computational fluid...

Fluidized bed agglomeration is used to produce large and porous dry agglomerates with improved instant properties. Water (or binder solution) is sprayed in the fluidized bed of particles to render their surface sticky. The agglomerate growth results from the repetition of different steps (wetting of the particle surface, particles collision and bridging, and drying) and depends on the processin...

The Government Accounting Office reports that the Department of Defense spends approximately $20 Billion per year on prevention and repair of corrosion. The resources required to combat corrosion problems are desperately needed for equipment and personnel in today's high operations tempo environment. Despite its significance, modeling for the spatial-temporal prediction of corrosion evolution h...