Measurements of Aerosol Size Distributions and Vertical Fluxes of Aerosols on Land Subject to Wind Erosion

To assess wind erosion as a source of atmospheric soil particles, vertical aerosol fluxes near the ground in an eroding field were computed by assuming a vertical transport mechanism similar to that for momentum. Aerosol gradients were measured by jet impactors located 1.5 and 6 m above the ground, and wind velocity gradients were measured by totalizing-three anemometers located 1.5, 3 and 6 m above the ground. Information on the aerosol size distributions and quantity in the size range 0.

Threshold Friction Velocities and Rupture Moduli for Crusted Desert Soils for the Input of Soil Particles into the Air

Desert soils having clay crusts, mostly from the Mojave Desert, were tested for threshold friction velocity (the friction velocity at which soil erosion begins) with an open-bottomed wind tunnel. The soils were also tested for content of clay, water-soluble material, calcium carbonate, organic material, mineralogy of clay and of salts, soil moisture, modulus of rupture, and crust thickness. If no loose material existed on the soil surface, crusts having modulus of rupture greater than 0.7 bar and crust thickness of 0.7 cm to 0.3 cm were effective in protecting against wind erosion. Disturbed clay crusts having modulus of rupture before disturbance greater than 2 bar with thickness less than 1.9 cm did not experience significant wind erosion. Modulus of rupture was related to composition of soil but was shown to depend mostly on clay content. Soil composition is related to modulus of rupture in an empirical equation

Threshold Friction Velocities and Rupture Moduli for Crusted Desert Soils for the Input of Soil Particles into the Air

Desert soils having clay crusts, mostly from the Mojave Desert, were tested for threshold friction velocity (the friction velocity at which soil erosion begins) with an open-bottomed wind tunnel. The soils were also tested for content of clay, water-soluble material, calcium carbonate, organic material, mineralogy of clay and of salts, soil moisture, modulus of rupture, and crust thickness. If no loose material existed on the soil surface, crusts having modulus of rupture greater than 0.7 bar and crust thickness of 0.7 cm to 0.3 cm were effective in protecting against wind erosion. Disturbed clay crusts having modulus of rupture before disturbance greater than 2 bar with thickness less than 1.9 cm did not experience significant wind erosion. Modulus of rupture was related to composition of soil but was shown to depend mostly on clay content. Soil composition is related to modulus of rupture in an empirical equation

Measurements of Aerosol Size Distributions and Vertical Fluxes of Aerosols on Land Subject to Wind Erosion

To assess wind erosion as a source of atmospheric soil particles, vertical aerosol fluxes near the ground in an eroding field were computed by assuming a vertical transport mechanism similar to that for momentum. Aerosol gradients were measured by jet impactors located 1.5 and 6 m above the ground, and wind velocity gradients were measured by totalizing-three anemometers located 1.5, 3 and 6 m above the ground. Information on the aerosol size distributions and quantity in the size range 0.

Physics of windblown particles

A laboratory facility proposed for the Space Station to investigate fundamental aspects of windblown particles is described. The experiments would take advantage of the environment afforded in earth orbit and would be an extension of research currently being conducted on the geology and physics of windblown sediments on earth, Mars, and Venus. Aeolian (wind) processes are reviewed in the planetary context, the scientific rational is given for specific experiments to be conducted, the experiment apparatus (the Carousel Wind Tunnel, or CWT) is described, and a plan presented for implementing the proposed research program

A study of aging of lead aerosols

http://deepblue.lib.umich.edu/bitstream/2027.42/5072/5/bac2701.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/5072/4/bac2701.0001.001.tx

Breaks, Good and Bad: The Inner Life of Research

Once in a while, if you are lucky, you will get to read a technical research article which has some soul. The rest are corpses. Corpses are fine for their purpose, but they never real the inner life, the dynamic mechanism. An outstanding exception is the recent best seller in science, The Double Helix; which details the very human development of a very important theoretical model.</p