Inhalation of tobacco smoke aerosol is a two-step process involving puffing followed by inhalation. Measured smoke deposition efficiencies in the lung (20-70%) are greater than expected for smoke particles of diameter 150 – 250 nm CMD. Various mechanisms have been put forward to explain this enhanced deposition pattern, including coagulation, hygroscopic growth, condensation and evaporation, ch...

Acoustic vibrations of single gold nanorods coated with silver were investigated. We used single-particle pump-probe spectroscopy to monitor the silver deposition through the particle vibrations. Two vibration modes, the breathing mode and extensional mode, are observed, and the vibrational frequencies are measured as functions of the amount of silver deposited on single gold nanorods. The brea...

In this work the dynamic flow as well as the particle motion and deposition in a commercial dry powder inhaler, DPI (i.e., Turbuhaler) is described using computational fluid dynamics, CFD. The dynamic flow model presented here is an extension of a steady flow model previously described in Milenkovic et al. (2013). The model integrates CFD simulations for dynamic flow, an Eulerian-fluid/Lagrangi...

Deposition fractions of inhaled particles predicted by different computational models vary with respect to physical and biological factors and mathematical modeling techniques. These models must be validated by comparison with available experimental data. Experimental data supplied by different deposition studies with surrogate airway models or lung casts were used in this study to evaluate the...

A theoretical model was developed to calculate the deposition of inhaled fibrous particles in the human lung. In the derivation of deposition formulae, the simultaneous effects of the velocity shear in the air flow and Brownian rotation on particle orientation were considered. Total deposition of fibers in the lung at mouth breathing was found to be smaller than that of spherical ones with the ...

important experiments on total and regional lung deposition for healthy subjects has recently been published by the International Commission on Radiation Protection (ICRP) [2]. The mean values of experimental deposition data are approximated by mathematical expressions, which are then implemented into a computer program [3] that is commercially available on diskette. Since this model is applica...

The capture efficiency of the small aerosol particle is strongly influenced by the structure of fibrous layers. This study presents particle deposition and dendrite formation on different arrangements of binary fibers. 2-D numerical simulation is performed using the open source software of OpenFOAM. In the instantaneous filtration of a single fiber, obtained results are in good agreement with th...

Comparison of experimental and computational results of aerosol deposition in the oro-pharyngeal cast of human published recently (Sosnowski TR, Moskal A, Gradoń L. (2006) Inhal Toxicol; 18: 773-780) demonstrated the applicability and relevance of considering realistic breathing patterns in analysis of aerosol flow and deposition within the human head airways. This issue is extended in the curr...

In this paper, we present a methodology for simulating pressure drop and collection efficiency of a filter medium during instantaneous particle loading using the ANSYS–Fluent CFD code, enhanced with inhouse subroutines. The simulations are comprised of a numerical solution of the Stokes equations for obtaining the air flow field, and Lagrangian particle tracking, for determining the particle co...

The purpose of this paper is to present a method for estimating particle doses that may be used to reconcile particle deposition doses used in in vitro toxicology studies with in vivo exposure levels. The focus is on the tracheobronchial (TB) tree of heavily exposed individuals. A review of the factors that influence inhaled particle deposition doses in environmental exposures leads to the iden...