Aerodynamics, nose

The aerodynamic particle diameter determines the fate of particles in the respiratory system. Coarse particles are deposited in the nose and nasopharynx. Smaller particles that pass the upper airway can be deposited in the bronchial region and lower airway. A size-selective deposition model and sampling of particles has been standardized both in Europe and internationally. The... 

The net aerodynamic force exerted on a body is illustrated in Figure 2 by the arrow labeled R. The direction and speed of the airflow ahead of the body is denoted by V, called the relative wind. The body is inclined to V . by the angle of attack, a. The resultant aerodynamic force R can be resolved into two components lift, L, perpendicular to V. and drag, D, parallel to V,. In Figure 2, R is shown acting through a point one-quarter of the body length from the nose, the quarter-chord point. Beacuse the aerodynamic... 

Respirable particles are 10 or less micrometers in aerodynamic diameter. The sources of respirable particles include kerosene heaters, paint pigments, insecticide dusts, radon, and asbestos. The particles may irritate the eyes, nose, and throat and may contribute to respiratory infections, bronchitis, and lung cancer. 

About 14 types of nose fuzes (of which 4 types are VT fuze) are used in GP bombs, old series, in addn to 8 types in tail fuzes New Series GP Bombs are not listed in Ref 44, but two of such bombs 750-lb Ml 17 and 3000-lb Ml 2 8 are described in Ref 51a, pp 2-26. 2-27. They are designed for high blast effects and for improved aerodynamic performance accuracy in flight when released from most altitudes and airspeeds. Their bodies are cigarshaped with a conical fin-assembly bolted to the rear. This can be seen from Fig 2-5. The Fig 2-20 of Ref 51a showing their cutaway view is not reproduced here because its lines are too faint to understand the inside construction... 

We routinely use nose-only inhalation exposure of B(a)P aerosol to evaluate the consequence of prenatal exposure to this toxicant on physiological and behavioral endpoints. The properties of this B(a)P aerosol are shown in Figure 17.4. The aerosol typically exhibits a trimodal distribution with a 93% cumulative mass less than 5.85 pm, 89% cumulative mass less than 10 pm, 55.3% cumulative mass less than 2.5 pm, and 38% less than 1 pm. Fifty-five percent of the aerosol generally has a cumulative mass less than PM2.5 and the mass median aerodynamic diameter (MMAD) + geometric standard deviation for this mode is consistently 1.7 =E 0.085 pm. For several years we employed a rat model exposing timed pregnant dams to inhalation concentrations of 25, 75, and 100 pg/m. ... 

Baldwin et al. (2001) exposed 6-month-old Fischer 344 rats to room air or JP-8 aerosols alone or to JP-8 and then aerosolized substance P, which has been shown to attenuate the effects of JP-8-induced pulmonary dysfunction and immunotoxicity in animals. Inhalation exposures were nose-only and performed 1 hr/day, 5 days/wk for 28 days. Aerosolized JP-8 with a mass mean aerodynamic diameter (MMAD) of 1.7-1.9 pm (M. Witten, University of Arizona, personal communication, 2002) was administered to the rats at... 

In contrast with the results by Mattie et al. (1991), Harris et al. (1997a,b,c, 2000) reported significantimmunopathologic effects in C57B1/6 mice exposed nose-only to aerosolized JP-8 (with a median mass aerodynamic diameter [MM AD] of 1.7-1.9 pm M. Witten, University of Arizona, personal communication, 2002). Reported exposure at 100 mg/m3 for 1 hr/day for 7 days resulted in decreased cellularity of the thymus gland while exposure at 500 mg/m3 for 1 hr/day for 7 days resulted in decreased spleen weight and cellu-... 

Miller et al. (1988) have experimentally determined regional deposition of particulates in nose and mouth breathers for 1 pm aerodynamic diameter particles (Table... 

To gain an indication of the most suitable aerodynamic shape for the cab a number of full-scale trials were undertaken using a mock-up cab fitted to the front of a conventional electric locomotive. The experimental cab was constructed from single-skin GRP and its nose angle, when fitted to the locomotive, made adjustable. Pressure sensing equipment was installed in the locomotive to record the optimum cab position under a variety of operating conditions tests indicated that an angle of 40° to the vertical was the most satisfactory. 

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