Determination of Size-Dependent Dry Particle Deposition Velocities with Multiple Intrinsic Elemental Tracers

1998 ◽  
Vol 32 (11) ◽  
pp. 1615-1622 ◽  
Author(s):  
Peter F. Caffrey ◽  
John M. Ondov ◽  
Maria J. Zufall ◽  
Cliff I. Davidson
Keyword(s):  
Particle Deposition ◽  
Size Dependent ◽  
Deposition Velocities

A Laser Doppler Method for the determination of particle deposition velocities

1989 ◽  
Vol 20 (3) ◽  
pp. 381-390 ◽  
Author(s):  
W. Holländer ◽  
G. Pohlmann ◽  
G. Morawietz
Keyword(s):  
Particle Deposition ◽  
Laser Doppler ◽  
Doppler Method ◽  
Deposition Velocities

scholarly journals First-Principles Determination of the Polarizabilities of Carbon Tubules as a Function of Length

1994 ◽  
Vol 349 ◽  
Author(s):  
Andrew A. Quong ◽  
Mark R. Pederson
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Valence Electron ◽  
Local Density ◽  
Density Approximation ◽  
Functional Theory ◽  
Size Dependent ◽  
The Density Functional Theory ◽  
Linear And Nonlinear

ABSTRACTWe use the local-density-approximation to the density-functional theory to determine the axial polarizabilities of fullerene tubules as a function of length and winding topologies. Specifically, we present linear polarizabilities for tubules of composition C12H24, C36H24, C40H20 and C60H24. The size-dependent variation in the dipole-coupled gaps between pairs of occupied and unoccupied levels leads to enhancements in the polarizability per valence electron as the length of the tubule increases. The results are compared to recent densityfunctional based calculations of the linear and nonlinear polarizabilities for fullerene and benzene molecules.

Techniques for the Determination of Particle Deposition in Lungs of Hamsters

1989 ◽  
Vol 2 (3) ◽  
pp. 247-259 ◽  
Author(s):  
VINZENZ IM HOF ◽  
GERHARD SCHEUCH ◽  
MARIANNE GEISER ◽  
JOSEPH GEBHART ◽  
PETER GEHR ◽  
...  
Keyword(s):  
Particle Deposition

Measured Effects of Reduced Flow Velocity in a Laminar Flow Cleanroom

1994 ◽  
Vol 37 (3) ◽  
pp. 41-46
Author(s):  
Peter Carr ◽  
Angelo Rapa ◽  
William Fosnight ◽  
Robert Baseman ◽  
Douglas Cooper
Keyword(s):  
Laminar Flow ◽  
Particle Deposition ◽  
Deposition Velocity ◽  
Equivalent Diameter ◽  
Surface Deposition ◽  
Deposition Velocities ◽  
Airborne Concentration ◽  
Class 1 ◽  
Surface Particle ◽  
Contamination Levels

Vertical laminar flow (VLF) cleanrooms generally operate with airflows between 60 feet per minute (fpm) and 110 fpm. Tests were performed to evaluate the effects on particle contamination levels when the airflow velocity in a FED-STD-209 Class 1 VLF cleanroom was reduced. The cleanroom normally operates at 90 fpm. Measurements of surface particle concentrations were made on settling monitor wafers and on wafers carried in an open cassette. Optical particle counters measured the airborne particle concentrations at several locations. Results at 100 fpm and 50 fpm, respectively, for particles larger than or equal to 0.3 μm in optical equivalent diameter were −0.0002 and +0.0029 particles/sq cm/hr for the settling wafers and 0.009 and 0.024/sq cm total for the wafers carried for 5 hr in the open cassettes. Summary statistics are provided for the airborne and surface particle counts. Deposition velocity is the ratio of surface deposition rate to airborne concentration. For the monitor wafers at the lower flow, the calculated particle deposition velocities were near 0.003 cm/sec, which is within the range expected from theory and experiments in the literature.

Sign in / Sign up

Export Citation Format

Share Document