23,041 research outputs found
Influence of organic films on the evaporation and condensation of water in aerosol
Uncertainties in quantifying the kinetics of evaporation and condensation of water from atmospheric aerosol are a significant contributor to the uncertainty in predicting cloud droplet number and the indirect effect of aerosols on climate. The influence of aerosol particle surface composition, particularly the impact of surface active organic films, on the condensation and evaporation coefficients remains ambiguous. Here, we report measurements of the influence of organic films on the evaporation and condensation of water from aerosol particles. Significant reductions in the evaporation coefficient are shown to result when condensed films are formed by monolayers of long-chain alcohols [C(n)H((2n+1))OH], with the value decreasing from 2.4 × 10(−3) to 1.7 × 10(−5) as n increases from 12 to 17. Temperature-dependent measurements confirm that a condensed film of long-range order must be formed to suppress the evaporation coefficient below 0.05. The condensation of water on a droplet coated in a condensed film is shown to be fast, with strong coherence of the long-chain alcohol molecules leading to islanding as the water droplet grows, opening up broad areas of uncoated surface on which water can condense rapidly. We conclude that multicomponent composition of organic films on the surface of atmospheric aerosol particles is likely to preclude the formation of condensed films and that the kinetics of water condensation during the activation of aerosol to form cloud droplets is likely to remain rapid
Weight evolution in patients after stavudine substitution for lipoatrophy in Rwanda: comparison of zidovudine with tenofovir/abacavir
Mexico AIDS Conference 200
High temperature materials study
High temperature operating electronic devices for vapor deposition reactor syste
High-temperature-materials study
Chemical vapor deposition of aluminum phosphides onto single crystals of silicon and gallium arsenide for producing high temperature operating solid state electronic device
Retransmission of water resources data using the ERTS-1 data collection system
There are no author-identified significant results in this report
Risk factors for hepatotoxicity of nevirapine-containing antiretroviral drug regimens in a large antiretroviral treatment program in Rwanda
Mexico AIDS Conference 200
Future air traffic - A study of the terminal area
Systems analysis approach to airport planning and predicting terminal facility and aircraft demands in year 2000 for air traffic control system
First Opinion: A Deep-Ocean Odyssey Envisioning Giant Squid through Multimodal Nonfiction Poetry
A Parallax Distance to the Microquasar GRS 1915+105 and a Revised Estimate of its Black Hole Mass
Using the Very Long Baseline Array, we have measured a trigonometric parallax
for the micro quasar GRS 1915+105, which contains a black hole and a K-giant
companion. This yields a direct distance estimate of 8.6 (+2.0,-1.6) kpc and a
revised estimate for the mass of the black hole of 12.4 (+2.0,-1.8) Msun. GRS
1915+105 is at about the same distance as some HII regions and water masers
associated with high-mass star formation in the Sagittarius spiral arm of the
Galaxy. The absolute proper motion of GRS 1915+105 is -3.19 +/- 0.03 mas/y and
-6.24 +/- 0.05 mas/y toward the east and north, respectively, which corresponds
to a modest peculiar speed of 22 +/-24 km/s at the parallax distance,
suggesting that the binary did not receive a large velocity kick when the black
hole formed. On one observational epoch, GRS 1915+105 displayed superluminal
motion along the direction of its approaching jet. Considering previous
observations of jet motions, the jet in GRS 1915+105 can be modeled with a jet
inclination to the line of sight of 60 +/- 5 deg and a variable flow speed
between 0.65c and 0.81c, which possibly indicates deceleration of the jet at
distances from the black hole >2000 AU. Finally, using our measurements of
distance and estimates of black hole mass and inclination, we provisionally
confirm our earlier result that the black hole is spinning very rapidly.Comment: 20 pages; 2 tables; 6 figure
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