We describe an approach to studying grain structure formation in polycrystalline thin films during deposition from the vapor phase using a “grain continuum” representation of the solid. We employ three codes in concert to track the development of grains while accounting for ballistic transport and surface reaction kinetics. We show that higher precursor reactivities might well lead to higher vo...

The Langmuir-Blodgett (LB) technique is an elegant protocol for the steered assembly of metal nanoparticles, the deposition pressure serving as a convenient parameter to tune the assembly. Adsorption of nanoparticles from the subphase to the air-water interface can provide further control of the process. Citrate-stabilized gold nanoparticles in the aqueous subphase are shown to assemble into ex...

Nanostructured BiVO4 films were synthesized by coevaporation of bismuth and vanadium in an oxygen ambient, a process referred to as reactive ballistic deposition (RBD). The films were tested in various electrolyte solutions to assess their activity for photoelectrochemical water oxidation. Deposition parameters, including the V/Bi atomic flux ratio and the incident angle of deposition, were adj...

In this paper experimental results of the silnne oxidation kinetics in a rapid thermal low pressure chemical vapor deposition (RTLPCVD) cold wall reactor at 450 OC are presented. For a certain total pressure kept constant in the range of 0.6-4.5 mbar. it is always found a certain threshold silane partial pressure p(th)siH4 (decreasing from 0.15 mbar to 0.076 n~bnr whcn the total pressure increa...

To improve the thermal and mechanical stability of SiCf/SiC or C/SiC composites with SiBN interphase, SiBN coating was deposited by low pressure chemical vapor deposition (LPCVD) using SiCl₄-BCl₃-NH₃-H₂-Ar gas system. The effect of the SiCl₄ flow rate on deposition kinetics was investigated. Results show that deposition rate increases at first and then decreases with the increase of the SiCl₄ f...

A discrete version of deposition-diffusion equations appropriate for description of step flow on a vicinal surface is analyzed for a two-dimensional grid of adsorption sites representing the stepped surface and explicitly incorporating kinks along the step edges. Model energetics and kinetics appropriately account for binding of adatoms at steps and kinks, distinct terrace and edge diffusion ra...

this paper investigates the importance of considering biomass growth and decay for predicting a field scale microbial degradation of btex plume in an unconfined aquifer system in the pump station area of tehran oil refinery (tor), iran. a two-dimensional finite volume model has been presented to predict multi-species reactive transport incorporating physical, chemical and biological processes i...

In this study, we present the response of model results to different scientific treatments in an effort to quantify the uncertainties caused by the incomplete understanding of mercury science and by model assumptions in atmospheric mercury models. Two sets of sensitivity simulations were performed to assess the uncertainties using modified versions of CMAQ-Hg in a 36-km Continental United State...

Chemical vapor deposition (CVD) is a process that solid formed on substrate by the chemical reaction in phase. Employing this technology, wide range of materials, including ceramic nanocomposite coatings, dielectrics, and single crystalline silicon can be coated variety substrates. Among factors influencing design CVD system are dimensions or geometry substrate, temperature, composition type pr...