Národní úložiště šedé literatury Nalezeno 2 záznamů.  Hledání trvalo 0.01 vteřin. 
In Vitro Study of the Effect of Particle Characteristics and Flow Rate on Regional Deposition in Human Airways
Bělka, Miloslav ; Adamec, Vladimír (oponent) ; Farkas, Árpád (oponent) ; Jedelský, Jan (vedoucí práce)
Inhalation of airborne particulate matter can trigger or exacerbate pre–existing lung conditions. On the other hand, inhalation of aerosolized medicaments can be used for treatment of various respiratory or systemic diseases. In both cases, it is essential to comprehend the particle transport and subsequent deposition. The aim of this PhD thesis is to obtain new experimental data on particle deposition and elucidate the effect of particle shape and flow rate on deposition. The deposition of porous and fibrous particles in the realistic replica of human respiratory airways was studied. The porous particles were produced by various methods, such as spray–drying or liquid–liquid interface crystallization. The produced particles were introduced into the replica and the subsequent deposition was detected using spectrophotometry. The fibrous particles were produced by crushing glass wool material. To narrow the fiber size distribution, the resulting fibers were sieved and then classified according to their length using a dielectrophoretic classifier. The fiber deposition inside the replica was detected using phase–contrast microscopy. To speed–up this analysis, an in–house software based on image processing was developed. The results were utilized to calculate deposition characteristics. The deposition efficiency of both particle types increased with increasing Stokes number indicating a significant role of impaction. Comparing their deposition efficiency to that of spherical particles, porous particles exhibited similar deposition efficiencies, however, fibers deposited less efficiently than spherical particles having the same Stokes number. As the boundary conditions were sufficiently described and the replica is available in a digital format, the data can be also employed in validation of numerical simulations.
In Vitro Study of the Effect of Particle Characteristics and Flow Rate on Regional Deposition in Human Airways
Bělka, Miloslav ; Adamec, Vladimír (oponent) ; Farkas, Árpád (oponent) ; Jedelský, Jan (vedoucí práce)
Inhalation of airborne particulate matter can trigger or exacerbate pre–existing lung conditions. On the other hand, inhalation of aerosolized medicaments can be used for treatment of various respiratory or systemic diseases. In both cases, it is essential to comprehend the particle transport and subsequent deposition. The aim of this PhD thesis is to obtain new experimental data on particle deposition and elucidate the effect of particle shape and flow rate on deposition. The deposition of porous and fibrous particles in the realistic replica of human respiratory airways was studied. The porous particles were produced by various methods, such as spray–drying or liquid–liquid interface crystallization. The produced particles were introduced into the replica and the subsequent deposition was detected using spectrophotometry. The fibrous particles were produced by crushing glass wool material. To narrow the fiber size distribution, the resulting fibers were sieved and then classified according to their length using a dielectrophoretic classifier. The fiber deposition inside the replica was detected using phase–contrast microscopy. To speed–up this analysis, an in–house software based on image processing was developed. The results were utilized to calculate deposition characteristics. The deposition efficiency of both particle types increased with increasing Stokes number indicating a significant role of impaction. Comparing their deposition efficiency to that of spherical particles, porous particles exhibited similar deposition efficiencies, however, fibers deposited less efficiently than spherical particles having the same Stokes number. As the boundary conditions were sufficiently described and the replica is available in a digital format, the data can be also employed in validation of numerical simulations.

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