scholarly journals Deposition of combustion aerosols in the human respiratory tract: Comparison of theoretical predictions with experimental data considering nonspherical shape

2009 ◽  
Vol 21 (14) ◽  
pp. 1154-1164 ◽  
Author(s):  
W. Hofmann ◽  
L. Morawska ◽  
R. Winkler-Heil ◽  
M. Moustafa
1965 ◽  
Vol 43 (1) ◽  
pp. 157-172 ◽  
Author(s):  
J. M. Beeckmans

The deposition of aerosol in the human respiratory tract was calculated as a function of the particle size and particle density of the aerosol, the manner of breathing, and various parameters which control the degree of mixing of inspired air with the dead space air and with the lung air. The computations were performed on an electronic computer, which allowed a full analysis of the effects of the various parameters. Agreement between the computed total deposition curves, and published experimental data was very satisfactory. The computed curves exhibited the minimum in total deposition previously established experimentally, in the region of 0.3 μ. The maximum in the alveolar deposition curve was about 1 μ for particles of unit density, confirming the results of Brown, Cook, Ney, and Hatch for nose breathing. Its position was a function of the density of the aerosol particles, but was relatively insensitive to the tidal volume and other breathing parameters. The opposite held in regard to the value of the maximum, which was totally uninfluenced by the particle density, but was affected by the breathing parameters.


2005 ◽  
Vol 36 (8) ◽  
pp. 939-957 ◽  
Author(s):  
Lidia Morawska ◽  
Werner Hofmann ◽  
Jane Hitchins-Loveday ◽  
Cheryl Swanson ◽  
Kerrie Mengersen

AIHAJ ◽  
1979 ◽  
Vol 40 (12) ◽  
pp. 1055-1066 ◽  
Author(s):  
E. AUSTIN ◽  
J. BROCK ◽  
E. WISSLER

Author(s):  
Digamber Singh

The human respiratory tract has a complex airflow pattern. If any obstruction is present in the airways, it will change the airflow pattern and deposit particles inside the airways. This is the concern of breath quality (inspired air), and it is decreasing due to the unplanned production of material goods. This is a primary cause of respiratory illness (asthma, cancer, etc.). Therefore, it is important to identify the flow characteristics in the human airways and airways with a glomus tumour with particle deposition. A numerical diagnosis is presented with an asymmetric unsteady-state light breathing condition (10 l/min). An in vitro human respiratory tract model has been reconstructed using computed tomography scan techniques and an artificial glomus tumour developed 2 cm above a carina on the posterior wall of the trachea. The transient flow characteristics are numerically simulated with a realizable (low Reynolds number) k–ɛ turbulence model. The flow disturbance is captured around the tumour, which influenced the upstream and downstream of the flow. The flow velocity pattern, wall shear stress and probable area of inflammation (hotspot) due to suspended particle deposition are determined, which may assist doctors more effectively in aerosol therapy and prosthetics of human airways illness.


Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.


1993 ◽  
Vol 16 (2) ◽  
pp. 63-70 ◽  
Author(s):  
N.A. Hoenich ◽  
P.T. Smirthwaite ◽  
C. Woffindin ◽  
P. Lancaster ◽  
T.H. Frost ◽  
...  

Recirculation is an important factor in single needle dialysis and, if high, can compromise treatment efficiency. To provide information regarding recirculation characteristics of access devices used in single needle dialysis, we have developed a new technique to characterise recirculation and have used this to measure the recirculation of a Terumo 15G fistula needle and a VasCath SC2300 single lumen catheter. The experimentally obtained results agreed well with those established clinically (8.5 ± 2.4% and 18.4 ± 3.4%). The experimental results have also demonstrated a dependence on access type, pump speeds and fistula flow rate. A comparison of experimental data with theoretical predictions showed that the latter exceeded those measured with the largest contribution being due to the experimental fistula.


2004 ◽  
Vol 86 (4) ◽  
pp. 337-352 ◽  
Author(s):  
Eduardo B. Farfán ◽  
Eun Young Han ◽  
Wesley E. Bolch ◽  
ChulHaeng Huh ◽  
Thomas E. Huston ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document